Use 'ref' over 'branch' and make optional for external.
Don't pass branch to Grit clone.
Need to pass ref to grit clone.
Add punctuation to some comments.
Added Inline Docs badge.
Revert "Added Inline Docs badge."

This reverts commit 7420d187dfc65fbbe94c931af13aadfbc24afe44.
Use flat badge style.
Merge branch 'master' into refactor

Conflicts:
	lib/palimpsest/assets.rb
	lib/palimpsest/environment.rb
	lib/palimpsest/external.rb
	spec/environment_spec.rb
	spec/external_spec.rb