v0.7.1

• Resolve ember executable with full path within node_modules, instead of
  depending on the presence of node_modules/.bin. #395
• Introduce the idea of App#mountable? and App#to_rack for handling deploys
  that don't serve assets from the file system (Redis, for example).
• Fix bug with generated bin/heroku_install script iterating through multiple
• Don't mount route helpers at top-level. Instead, mount within the surrounding
  context with which they're invoked. #381