title: android gradle, use different dependency version in android testing environment
body: <p>I have a project that depends on a dependency, say 'mygroup:myartifect:myversion', normally I would add this to my build.gradle</p>
  
  <pre><code>compile 'mygroup:myartifect:myversion'
  </code></pre>
  
  <p>but during android test, I would like to use a different version of the same dependency, say myversion2. If I add </p>
  
  <pre><code>androidTestCompile 'mygroup:myartifect:myversion2'
  </code></pre>
  
  <p>I would run into an error said: </p>
  
  <pre><code>Error:Execution failed for task ':app:processDebugAndroidTestResources'.
  &gt; Error: more than one library with package name 'mygroup.myartifect'
  </code></pre>
  
  <p>How can I achieve this?</p>