fix ActiveRecord::AttributeMethods::Dirty patch

was out of date with rails 4.1.4 which was preventing attribute *_was
fields from being calculated correctly for enum fields.
Merge pull request #226 from zsalzbank/dirty_fix

fix ActiveRecord::AttributeMethods::Dirty patch
Modernize read and write methods now that dirty methods are updated.
Version 7.0.10
Implement id_was for rails 4.1.6 compatibility
Merge branch 'master' of github.com:composite-primary-keys/composite_primary_keys into run_default_ar_update
Merge pull request #236 from tomhughes/id_was

Implement id_was for rails 4.1.6 compatibility
Revert "Implement id_was for rails 4.1.6 compatibility"
Merge pull request #244 from composite-primary-keys/revert-236-id_was

Revert "Implement id_was for rails 4.1.6 compatibility"
Fix for ActiveRecord 4.1.6.  id_was used to be based on attribute_was, but is not a separate method.  Fixes #236.
Fix up require changes for last patch.
Update gem to 7.0.11 and update AR version requirements.
Fix binary column issue. #187.
Fix deleting records, uncomment out old tests that caused this issue to be missed. #229.
Updated history.
Manually add info about 6.0.7 release.
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'
Merge pull request #249 from shiro16/ar_4.1.x

fixed active_model/dirty (LoadError)
Remove unneeded require.
Update to version 7.0.12