Update README to explain how to install grunt and bower

Only because I had to click around a bit before I figured out how to do
it.
Merge pull request #138 from jamesotron/more-setup-info

Update README to explain how to install grunt and bower
Start checking in builds
Use Ember.get() for rootKey in toJSON
Merge pull request #96 from raytiley/computed-rootKey

Use Ember.get() for rootKey in toJSON
Update build
Updated gitignore
Merge pull request #139 from raytiley/gitignore

Updated gitignore