show available equipment
remove and add equipment for rooms
look better
add first tests
free equipment after deleting room, assign equipment when creating a room, test
room show shows equipment of room
some tests
Merge branch 'Dolphins' into D/feature/#23

Conflicts:
	app/controllers/rooms_controller.rb
	config/locales/views/room.de.yml
	spec/controllers/rooms_controller_spec.rb
Merge pull request #193 from hpi-swt2/D/feature/#23

D/feature/#23