fix tests from rebasing master for embed_namespace
Merge pull request #461 from fivetanley/embed-in-root-key

Add embed_namespace and embed_in_root_key options
Allow users to opt-out from the ActionController extensions
Merge pull request #592 from byroot/disable-ac-extension

Allow users to opt-out from the ActionController extensions
Manually include AC::Serialization module in test suite
Merge pull request #593 from byroot/fix-tests-broken-by-592

Manually include AC::Serialization module in test suite
Fix leaky test global state
Remove some monkey patching