Trim error were thrown when linked ember-cli had deatched HEAD.

If the contents of the ./git/HEAD file does not return a ref path,
it's a SHA value so that is what will be used.
Merge pull request #641 from WMeldon/master

Trim error was thrown when linked ember-cli had detached HEAD.
Do not export full vendor tree.
Merge pull request #645 from rjackson/do-not-export-all-of-vendor

Do not export full vendor tree.
Update Broccoli to 0.12.
Merge pull request #648 from rjackson/update-broccoli

Update Broccoli to 0.12.
WIP
Drop loom-generators-ember-appkit from package.json template
Add literate test helpers
Add support for type on controller blueprint
Add component blueprint
Add helper test
Update test to kebab-case helper