title: .gitignore and git rm --cached wont keep files from being tracked
body: <p>I have an android project that has a test module that will remove and recreate .apk files in a  subdirectory in the git directory.</p>
  
  <p>I have added these to .gitignore (the directory, the files explicitly, and *.apk ) and then I have done</p>
  
  <pre><code>git rm -r --cached src/main/Tests/bin
  </code></pre>
  
  <p>and git tells me:</p>
  
  <pre><code>rm 'src/main/Tests/bin/Tests-debug-unaligned.apk'
  rm 'src/main/Tests/bin/Tests-debug.apk'
  rm 'src/main/Tests/bin/Tests.ap_'
  rm 'src/main/Tests/bin/classes.dex'
  </code></pre>
  
  <p>i then </p>
  
  <pre><code>git commit . -m "removed apk files"
  </code></pre>
  
  <p>I run the tests again which delete the files and the recreate them.  I run git status and they show up as modified.  It seems .gitignore is not working.  Here is my .gitignore file</p>
  
  <pre><code>*ipr
  *iml
  *iws
  .gitignore
  out/
  *apk
  src/main/Tests/bin
  src/main/Tests/bin/*
  src/main/Tests/bin/Tests-debug-unaligned.apk
  </code></pre>