Update documentation, add MariaDB support
Implement id_was for rails 4.1.6 compatibility
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.
Merge pull request #228 from irobayna/patch-1

Update documentation, add MariaDB support.
merge master