title: Test phase is grayed out in XCode 4
body: <p>I've been using GHUnit in my project because the built in unit testing was so terrible in XCode 3.</p>
  
  <p>However, now that they've been fixed in XCode 4, I want to switch back to the official testing framework.</p>
  
  <p>I added a new "Cocoa Touch Unit Testing Bundle", which also adds a test case designed to fail, but "Test" under the Product menu is still grayed out.</p>
  
  <p>What else do I need to do to get unit tests running in my project?</p>