Remove Ruby 1.9.2 support
Bump up the Active Record 4.0 gemfile dependencies out of beta
Use "double" rather than the deprecated "mock"
Update all of the gemfiles
Clean up .travis.yml

* Add missing Mongoid gemfiles
* Remove 1.9.2 exclusions (support dropped)
* Move default run to Ruby 2.0.0
Move back to Database Cleaner 0.9

Database Cleaner 1.0+ seems to have issues with some adapters.
Explicitly require DataMapper's SQLite adapter
Ensure proper load order for adapter-specific spec/support files
Allow accessible scope exclusion for blank value