Use gem acts_as_taggable for user interests. Gem is responsible for adding new polymorphic table tagging. User show page contain form for adding interests. We can add one or many interests in one line.
Add partial for interest
Merge branch 'interest_tagging'

Conflicts:
	app/views/users/show.html.haml
	db/schema.rb
	spec/features/adding_interests_spec.rb
Use acts_as_taggable_on for skills
Fix skill form
Use acts_as_taggable for skills
Merge branch 'skills_tagging'