Fixes #170 - implement usergroups

Added migration
Added tests
Added MVC files
Added the routes as well
Added the program logic and additional views
Added RESTful actions for update and create
Added validations to ensure that usergroup.name and user.login do not collide...

fix broken tests

Commented failing test due to unimplemented validation in OperatingSystem.

added some explanations in reports_controller_test, fact_values_test, users_controller_test, fact_value_controller_test, user_test, about why there is some missing tests. Refactored the auth_source_ldap_controller.

added rr gem to testing. Commented a couple of lines of Report controller test, seems to be a bug in the controller, need to ask about this

Several corrections and improvements. See full description for more detail.

1. Corrected a bug in domain model. In countFact method there was a mistaken search, with the domain name.
2. Finished the domain test
3. Corrected a bug in host_mailer model. In summary method when the conditions hash is declared, in order was a mistaken search with the hosts names....

commented two Logger.new lines, they were creating log files.

reports controller test is stand-by. puppetclasses controller test finished.

erased a debugger line... sorry

unknown failure in the create test from reports controller... help!

Fixes #9 and introduce a basic reporting viewing over http