add role for user and change user edit admin form
add lectors controller and routes
hide facebook button and fix user images
add topics model
add admin crud for topics
add chosen for user.topics
add lectors page filters
Merge branch 'feature/99_lectors_page' into develop

Conflicts:
	Gemfile
	app/views/layouts/web/admin/shared/_navigation.html.haml
	config/locales/ru.yml
	config/routes.rb