Add tags (gon usage)
Add test for tags, list of tags in exhibit, list of all exhibits with defined tag
Add uniqueness to tag
Delete gon, add tests
Edit tests
Delete unnecessary сomment lines
Tags in /admin and add tags in seeds.db
Delete gon from Gemfile
Edit routing test for tags
Merge branch 'master' into tags

Conflicts:
	Gemfile
	app/assets/javascripts/application.js
	app/assets/javascripts/exhibits.js.coffee
	app/controllers/exhibits_controller.rb
	app/views/exhibits/_form.html.haml
	config/routes.rb
	db/schema.rb
Make Select2 fit in with Bootstrap 3
Application into AdminPagesController
Edit tags controller test
Merge pull request #7 from SoftServeUniversity/tags

Add tags (gon usage)