title: Could not resolve dependency for 'com.google.firebase:firebase-auth:16.0.3'
body: <p>I am trying to add firebase authentication to my project. I am getting following errors while syncing <code>build.gradle</code>:</p>
  
  <pre><code>Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve com.google.firebase:firebase-auth:16.0.3.
  Unable to resolve dependency for ':app@debugAndroidTest/compileClasspath': Could not resolve com.google.firebase:firebase-auth:16.0.3.
  Unable to resolve dependency for ':app@debugUnitTest/compileClasspath': Could not resolve com.google.firebase:firebase-auth:16.0.3.
  Unable to resolve dependency for ':app@release/compileClasspath': Could not resolve com.google.firebase:firebase-auth:16.0.3.
  Unable to resolve dependency for ':app@releaseUnitTest/compileClasspath': Could not resolve com.google.firebase:firebase-auth:16.0.3.
  </code></pre>
  
  <p>My app level gradle file is below:</p>
  
  <pre><code>  apply plugin: 'com.android.application'
  
      android {
          compileSdkVersion 26
          defaultConfig {
              applicationId "com.example.muzammil.maptestingproject"
              minSdkVersion 15
              targetSdkVersion 24
              versionCode 1
              versionName "1.0"
              testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
          }
          buildTypes {
              release {
                  minifyEnabled false
                  proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
              }
          }
          productFlavors {
          }
      }
  
      dependencies {
          implementation fileTree(include: ['*.jar'], dir: 'libs')
          implementation 'com.android.support:appcompat-v7:26.1.0'
          implementation 'com.google.android.gms:play-services-maps:15.0.1'
          implementation 'com.google.android.gms:play-services-vision:15.0.2'
          implementation 'com.google.android.gms:play-services-location:15.0.1'
          implementation 'com.google.android.gms:play-services-maps:15.0.1'
  
  
          implementation 'com.google.firebase:firebase-core:16.0.3'
          implementation 'com.google.firebase:firebase-database:16.0.1'
          implementation 'com.android.support:design:26.1.0'
          implementation 'com.android.support.constraint:constraint-layout:1.1.2'
          implementation 'com.google.firebase:firebase-auth:16.0.3'
          testImplementation 'junit:junit:4.12'
          androidTestImplementation 'com.android.support.test:runner:1.0.2'
          androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
      }
      apply plugin: 'com.google.gms.google-services'
  </code></pre>
  
  <p>The project level gradle file is :</p>
  
  <pre><code> buildscript {
  
          repositories {
              google()
              jcenter()
          }
          dependencies {
              classpath 'com.android.tools.build:gradle:3.1.3'
             classpath 'com.google.gms:google-services:4.0.1'
          }
      }
  
      allprojects {
          repositories {
              google()
              jcenter()
   maven { url 'https://jitpack.io' }
          }
      }
  
      task clean(type: Delete) {
          delete rootProject.buildDir
      }
  </code></pre>