title: Make one source set dependent on another
body: <p>I have an integration test source set in gradle, and it is dependent on my main classes being compiled. I set that up by doing</p>
  
  <pre><code>integrationTestClasses.dependsOn 'classes'
  </code></pre>
  
  <p>Is this the way to do it, or is there a way to setup dependencies on source sets so this happens automatically? In my <code>configurations</code> block I already have</p>
  
  <pre><code>integrationTestCompile { extendsFrom testCompile }
  integrationTestRuntime { extendsFrom integrationTestCompile, testRuntime }
  </code></pre>