Extract active record application
Introduce mongoid2 application extension
Add extension for mongoid3
Add client support for mongo_mapper
Extract client association

Remove duplication since module has the same behaviour
Add active record generator for model

Based on devise generation
Generators for mongoid
Only execute active record generator if is the current orm
Add mongo mapper generators
Add doorkeeper tables migration
Update documentation
Effectively handle mongodb indexes requirements
Clean comments
Refactor similar mongoid extension into one module
Revert back destroy dependent tokens when application is deleted
Remove pry
Typo in README

[ci skip]
Ensure that client model is configured once
Different initializers for mongoid v2 and v3