add controller enabled to test helper

If your controller tests load before your model tests the test.rb
config will cause model test versions to not work even after setting
PaperTrail.enabled to true.

See:
https://github.com/bjallen/paper_trail/blob/6de04f199e7c6c885f922c231872
d04564fb931c/lib/paper_trail/has_paper_trail.rb#L391
close #406; close #401 Do not load the PaperTrail::Version class in via a Rails::Engine when used with Rails; feature pushed to 3.1.0
Bump to 3.0.4 [ci skip]
Load in Rails framework code
Bump to 3.0.5 [ci skip]
Merge branch '3.1.0-stable'

Conflicts:
	CHANGELOG.md
	lib/paper_trail.rb
Add documentation for where_object method
Merge pull request #424 from panorama-ed/feature/add-where_object-documentation

Add documentation for where_object method
Bump version number to 3.1.0.alpha [ci skip]
Serialization handler methods on PaperTrail::Model::ClassMethods should fall back to current serializer set under Config
Adjust README section for serializers to show full namespace of built-in modules [ci skip]
Fix reify method

Handle case old version has attribute with same name with current model setter
Merge pull request #427 from vinh0604/master

Close #427; Fix reify method with regards to attribute assignment
Update CHANGELOG [ci skip]
Add additional tutorial / blog post to Articles section on README [ci skip]
Fix PaperTrail::Model::InstanceMethods#changed_notably? to return proper values when attrs are ignored
Update Gadget spec with Ruby18 hash syntax
Add some additional testing and comments surrounding the PaperTrail::Model::InstanceMethods#changed_notably? private method changes
close #414; Merge branch 'fix-ignored-on-activerecord4'