Merge branch 'master' into v1.2.0
Update development dependencies
Update RuboCop configuration
Add UTF-8 comments
Fix #167; test multiple versions of ActiveModel
Add missing UTF-8 comment
Use more intention-revealing method name

The old one was plain wrong.
Merge branch 'master' into v1.2.0
Merge branch 'v1.2.0' into fake-columns-for-attributes