title: Github API: how to find the branches of a pull request?
body: <p>The Github API (v3) allows you to get a listing of pull requests, and get more details on an individual pull request. What I can't seem to find is the name of the branch the pull request is coming from and the branch the pull request is suggesting the code be merged into. </p>
  
  <p>Using the Github API how do you determine the branches involved in a pull request?</p>