title: Using additional library
body: <p>I am trying to use a custom calendar. (show it through xml-markup). But the app crash. What could be the reason? All I have done as it is written here. Made by Gradle manually inserting build.gradle. I have the same problem with other similar libraries, have already tried to use 5-6 libraries.
  xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  tools:context="com.example.denis.myplans.NewNoteActivity"&gt;
  
  &lt;com.imanoweb.calendarview.CustomCalendarView
      android:id="@+id/calendar_view"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:background="#ffffff"/&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>from error log:</p>
  
  <pre><code>  03-28 21:30:36.222 7338-7338/? E/AndroidRuntime: FATAL EXCEPTION: main
                                                   Process: com.example.denis.myplans, PID: 7338
                                                   java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.denis.myplans/com.example.denis.myplans.MainActivity}: android.view.InflateException: Binary XML file line #16: Error inflating class com.imanoweb.calendarview.CustomCalendarView
                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2521)
                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2601)
                                                       at android.app.ActivityThread.access$800(ActivityThread.java:178)
                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1470)
                                                       at android.os.Handler.dispatchMessage(Handler.java:111)
                                                       at android.os.Looper.loop(Looper.java:194)
                                                       at android.app.ActivityThread.main(ActivityThread.java:5637)
                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                       at java.lang.reflect.Method.invoke(Method.java:372)
                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                                                    Caused by: android.view.InflateException: Binary XML file line #16: Error inflating class com.imanoweb.calendarview.CustomCalendarView
                                                       at android.view.LayoutInflater.createView(LayoutInflater.java:633)
                                                       at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743)
                                                       at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
                                                       at android.view.LayoutInflater.parseInclude(LayoutInflater.java:916)
                                                       at android.view.LayoutInflater.rInflate(LayoutInflater.java:802)
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
                                                       at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:276)
                                                       at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
                                                       at com.example.denis.myplans.MainActivity.onCreate(MainActivity.java:19)
                                                       at android.app.Activity.performCreate(Activity.java:6112)
                                                       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1112)
                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2468)
                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2601) 
                                                       at android.app.ActivityThread.access$800(ActivityThread.java:178) 
                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1470) 
                                                       at android.os.Handler.dispatchMessage(Handler.java:111) 
                                                       at android.os.Looper.loop(Looper.java:194) 
                                                       at android.app.ActivityThread.main(ActivityThread.java:5637) 
                                                       at java.lang.reflect.Method.invoke(Native Method) 
                                                       at java.lang.reflect.Method.invoke(Method.java:372) 
                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960) 
                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 
                                                    Caused by: java.lang.reflect.InvocationTargetException
                                                       at java.lang.reflect.Constructor.newInstance(Native Method)
                                                       at java.lang.reflect.Constructor.newInstance(Constructor.java:288)
                                                       at android.view.LayoutInflater.createView(LayoutInflater.java:607)
                                                       at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743) 
                                                       at android.view.LayoutInflater.rInflate(LayoutInflater.java:806) 
                                                       at android.view.LayoutInflater.parseInclude(LayoutInflater.java:916) 
                                                       at android.view.LayoutInflater.rInflate(LayoutInflater.java:802) 
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:504) 
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
                                                       at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:276) 
                                                       at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139) 
                                                       at com.example.denis.myplans.MainActivity.onCreate(MainActivity.java:19) 
                                                       at android.app.Activity.performCreate(Activity.java:6112) 
                                                       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1112) 
                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2468) 
                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2601) 
                                                       at android.app.ActivityThread.access$800(ActivityThread.java:178) 
                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1470) 
                                                       at android.os.Handler.dispatchMessage(Handler.java:111) 
                                                       at android.os.Looper.loop(Looper.java:194) 
                                                       at android.app.ActivityThread.main(ActivityThread.java:5637) 
                                                       at java.lang.reflect.Method.invoke(Native Method) 
                                                       at java.lang.reflect.Method.invoke(Method.java:372) 
                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960) 
                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 
                                                    Caused by: java.lang.StringIndexOutOfBoundsException: length=2; regionStart=0; regionLength=3
                                                       at java.lang.String.startEndAndLength(String.java:504)
                                                       at java.lang.String.substring(String.java:1333)
                                                       at com.imanoweb.calendarview.CustomCalendarView.initializeWeekLayout(CustomCalendarView.java:171)
                                                       at com.imanoweb.calendarview.CustomCalendarView.refreshCalendar(CustomCalendarView.java:356)
                                                       at com.imanoweb.calendarview.CustomCalendarView.initializeCalendar(CustomCalendarView.java:132)
                                                       at com.imanoweb.calendarview.CustomCalendarView.&lt;init&gt;(CustomCalendarView.java:74)
                                                       at java.lang.reflect.Constructor.newInstance(Native Method) 
                                                       at java.lang.reflect.Constructor.newInstance(Constructor.java:288) 
                                                       at android.view.LayoutInflater.createView(LayoutInflater.java:607) 
                                                       at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743) 
                                                       at android.view.LayoutInflater.rInflate(LayoutInflater.java:806) 
                                                       at android.view.LayoutInflater.parseInclude(LayoutInflater.java:916) 
                                                       at android.view.LayoutInflater.rInflate(LayoutInflater.java:802) 
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:504) 
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
                                                       at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
                                                       at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:276) 
                                                       at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139) 
                                                       at com.example.denis.myplans.MainActivity.onCreate(MainActivity.java:19) 
                                                       at android.app.Activity.performCreate(Activity.java:6112) 
                                                       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1112) 
                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2468) 
                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2601) 
                                                       at android.app.ActivityThread.access$800(ActivityThread.java:178) 
                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1470) 
                                                       at android.os.Handler.dispatchMessage(Handler.java:111) 
                                                       at android.os.Looper.loop(Looper.java:194) 
                                                       at android.app.ActivityThread.main(ActivityThread.java:5637) 
                                                       at java.lang.reflect.Method.invoke(Native Method) 
                                                       at java.lang.reflect.Method.invoke(Method.java:372)
  </code></pre>
  
  <p>build.gradle</p>
  
  <pre><code> apply plugin: 'com.android.application'
  
      android {
          compileSdkVersion 23
          buildToolsVersion "23.0.2"
  
          defaultConfig {
              applicationId "com.example.denis.myplans"
              minSdkVersion 19
              targetSdkVersion 23
              versionCode 1
              versionName "1.0"
          }
          buildTypes {
              release {
                  minifyEnabled false
                  proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
              }
          }
      }
  
      dependencies {
          compile fileTree(dir: 'libs', include: ['*.jar'])
          testCompile 'junit:junit:4.12'
          compile 'com.android.support:appcompat-v7:23.2.1'
          compile 'com.android.support:design:23.2.1'
          compile 'com.github.npanigrahy:Custom-Calendar-View:v1.0'
      }
  </code></pre>
  
  <p>MainActivity.java</p>
  
  <pre><code>    package com.example.denis.myplans;
  
  import android.content.Intent;
  import android.os.Bundle;
  import android.support.design.widget.FloatingActionButton;
  
  import android.support.v7.app.AppCompatActivity;
  import android.support.v7.widget.Toolbar;
  import android.view.View;
  import android.view.Menu;
  import android.view.MenuItem;
  
  
  public class MainActivity extends AppCompatActivity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
          setSupportActionBar(toolbar);
  
          final Intent intNewNote = new Intent(this, NewNoteActivity.class);
          FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
          assert fab != null;
  
          fab.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  startActivity(intNewNote);
  
              }
          });
      }
  </code></pre>