title: Android Studio running unit test shows 'Empty test suite'
body: <p>I want to start writing unit tests for my applications but I cannot get one simple test to run.
  I have created a small application just to try how the unit test should be setup and run, but no test is actually run and I get 'Empty test suite'.</p>
  
  <p>I am using Android Studio 0.6.1 with gradle 1.12</p>
  
  <p>Here is my folder structure:</p>
  
  <p><img src="https://i.stack.imgur.com/OHbNR.png" alt="Folder structure"></p>
  
  <p>MyActivityTest.java</p>
  
  <pre><code>package com.vist.testableapp.tests;
  
  import android.content.Intent;
  import android.test.ActivityUnitTestCase;
  import android.test.suitebuilder.annotation.SmallTest;
  import android.widget.Button;
  
  import com.vist.testableapp.MyActivity;
  import com.vist.testableapp.R;
  
  public class MyActivityTest extends ActivityUnitTestCase&lt;MyActivity&gt;
  {
      public MyActivityTest(Class&lt;MyActivity&gt; activityClass)
      {
          super(activityClass);
      }
      Button btn1;
  
      @Override
      public void setUp() throws Exception
      {
          super.setUp();
  
          startActivity(new Intent(getInstrumentation().getTargetContext(), MyActivity.class), null, null);
          btn1 = (Button)getActivity().findViewById(R.id.button1);
      }
  
      @SmallTest
      public void testFirst()
      {
          assertEquals("Btn1",btn1.getText());
      }
  }
  </code></pre>
  
  <p>application's build.gradle</p>
  
  <pre><code>apply plugin: 'android'
  
  android {
      compileSdkVersion 19
      buildToolsVersion "19.1.0"
  
      defaultConfig {
          applicationId "com.vist.testableapp"
          minSdkVersion 15
          targetSdkVersion 15
          versionCode 1
          versionName "1.0"
          testApplicationId "com.vist.testableapp.tests"
  
      }
      buildTypes {
          release {
              runProguard false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
  }
  </code></pre>
  
  <p>Could anyone point out what am I doing wrong or what I am missing?
  I searched in SO but none of the answers helped me.</p>