Activate user group module

[2Fraennk]

The module 'icinga_user_group.py' cares about creating and administrating usergroups in icinga. To get it to work,...

• the module call was added to 'main/main.yml'
• the required dictionary was intialized in 'defaults/main.yml'
• the task 'tasks/icinga_user_group.yml' itself was added

To get it to work, the empty dictionary has just to be filled with groups. Please follow the example in the module's documentation.

[2Fraennk]

I just added the role parameters and the example call.

Because of it's growth the table seems a bit confusing to me. I prefer watching into the task's detailed doc.