composite-primary-keys/composite_primary_keys — pull request #249 by shiro16 (2014-10-08 10:56:03+00:00)
Title: fixed active_model/dirty (LoadError)

https://github.com/composite-primary-keys/composite_primary_keys/commit/c9d02647754cc403e5f35dbe54ed5f36507811bc
this commit remove active_model/dirty.rb but require 'active_model/dirty'