title: install gem from specific branch
body: <p><a href="https://stackoverflow.com/questions/2823492/install-gem-from-github-branch">Install Gem from Github Branch?</a></p>
  
  <p>I have been following the guide from that thread.  When I get to step 4, rake gem , I get an error </p>
  
  <p>rake aborted!
  Don't know how to build task 'gem'</p>