Fix bundler warning
Remove superfluous specification
whitespace
Fix mass assignment protection in Rails 4

AR4 sadly uses `alias` rather than `alias_method` to define
`#attributes`. This means we have to `alias_method_chain` `#attributes`
separately.
ActiveRecord adapter no longer forces hashes to be string-keyed
Merge pull request #117 from tamird/ar-preserve-hashes

ActiveRecord adapter no longer forces hashes to be string-keyed