Use AS 3 if ruby is < 1.9
Another attempt at fixing travis
Use platforms to restrict AS version
msgpack now works on ruby 2.0
Fix gemfile req
Cleanup gem reqs
Tests for cache digests implementation for Rails 4.
Tracker that is being used to track dependencies for `extends` and `partial` for each files.

Reference: https://github.com/rails/rails/blob/master/actionpack/lib/action_view/dependency_tracker.rb#L26
Custom digester for each file and its dependencies.  Inherited from `ActionView::Digestor`.

Reference: https://github.com/rails/rails/blob/master/actionpack/lib/action_view/digestor.rb
Special `cache_key` is being used by rails 4 from the custom `Rabl::Digester`.
Inject into Rails 4 so that the `cache digests` works.
Minor updates on the comment.
Preparing for cache digest merge
Makes Rails 2 fixture run again
Child now supports `object_root` and `root` arguments like 'collection'
Fixes failing tests re child options
Bump version to 0.9.0.pre
Add test for child name chosen properly based on symbol
FIX #486 Prioritize to_hash options to allow setting root
Update changelog