v0.5.0

• Deprecate include_ember_index_html in favor of the renamed
  render_ember_app.
• Always pass --environment test to Rails-generated ember test commands.
  #277
• No longer check dependencies within the app. Defer to EmberCLI's stderr
  streaming. #267
• Remove enable configuration in favor of using mount_ember_app. #261
• Introduce mount_ember_app route helper #263
• Remove support for viewing Ember tests through Rails. Instead, use ember test or ember test --serve from within the Ember directory. #264
• Remove build_timeout configuration #259
• Disable JS minification when generating Heroku setup #238
• BuildError#message includes first line of backtrace. #256
• Symlink dist/ directly to Asset Pipeline #250
• Merge EmberCLI-generated manifest.json into Sprocket's #250
• manifest.json. Since we now defer to EmberCLI, we no longer need to
  manually resolve asset URLs. #250