Updated gems version
Removed .ruby-version file from repository
Added ruby 2.1.0 to travis test
Deprecated all find_by_<attribute_name> and find_all_by<attribute_name> methods

Now find_by should be used instead of find_by_<attribute_name> and where instead of find_all_by_<attribute_name>
New mongoid no longer uses Moped namespace, considering both class names.
Removed :all option from find method
ActiveRepository objects can no longer have associations with ActiveRecord models
New active_record updates object's id, so no longer checking this as mongoid doesn't updates id
Normalizing id on find method, so it converts string ids when needed
Small refactor on base's where method
Small fixes on tests
Created ResultSet Class

Result Set is a class similar to ActiveRecord's Relation.