title: calabash testing setup, ANDROID_HOME path
body: <p>Im trying to use calabash and android for testing. So it is just a started and installed calabash. The problem comes when I try to execute the first test when I run:</p>
  
  <pre><code>calabash-android run myAPP.apk
  </code></pre>
  
  <p>I get a response:</p>
  
  <pre><code>`raise_if_android_home_not_set': Please set the ANDROID_HOME environment variable (RuntimeError)
  </code></pre>
  
  <p>How do I setup ANDROID_HOME?
  Where do I setup ANDROID_HOME?
  From your experience, do you recommend calabash?
  Thanks</p>