Authorization logic moved from ApplianceCreator into cancan

Inside `Atmosphere::ApplianceCreator` logic responsible for create authorization occurs. It was moved into cancan ability. 

Fixes redmine 3207 issue.

/cc @nowakowski, @djchrap, @Nuanda - please take a look. Deployed into `dev` - please test.
Since the definition of <pre>appliance_set.production?</pre> is <pre>not appliance_set_type.development?</pre> this is circular logic. I suggest substituting <pre>appliance_set.appliance_set_type.development?</pre>

Also note the hidden assumption that "not production" means "development". This may be true for now but given the enum-y nature of appliance_set_type we probably shouldn't be taking such shortcuts...