Merge pull request #39 from silasb/bump-version-from-upstream-3.3.2

Version bump from upstream to 3.3.2
Change Rails version dependency to >=
update assets to 3.4.0
Merge pull request #44 from benolee/update-assets-to-3.4.0

update assets to 3.4.0
remove sass-rails version
Merge pull request #45 from afiedler/master

Relax Rails dependency to support Rails 4
get file new select2.
update version 3.4.2 add rails 4.
update assets.