update gem to use mongoid 4
making mongoid-grid_fs not mandatory
Merge remote-tracking branch 'upstream/master'

Conflicts:
	carrierwave-mongoid.gemspec
fork gem
Merge branch 'master' of github.com:carrierwaveuploader/carrierwave-mongoid

Conflicts:
	README.md
	carrierwave-mongoid.gemspec
Fork gem
gems
update to carrierwave 0.9
add Gemfile.lock to git
bump version
gemfile.lock
do not define field if it's already defined
bump version
Gemfile.lock
don't redefine aliased fields
bump version
add ruby-version
Gemfile.lock
add to_s to field :as check
gemfile.lock