title: List all files changed in a pull request in Git/GitHub
body: <p>Is there a way (from the command line) to list the names of all files changed in a PR in Git/GitHub? This would be used to find what tests need to be run in a Travis CI build for that PR.</p>
  
  <p>The CI build runs these commands before it calls our script:</p>
  
  <pre><code>git clone --depth=50 git://github.com/jekyll/jekyll.git jekyll/jekyll
  cd jekyll/jekyll
  git fetch origin +refs/pull/2615/merge
  git checkout -qf FETCH_HEAD
  </code></pre>