Merge pull request #13 from thangnguyendinh/categories

categories
Delete edit.html (copy).erb
Delete new.html (copy).erb
Merge pull request #15 from thangnguyendinh/word

word and word answer
Delete categories_menu_controller.rb
Delete usersanswers.rb
Delete categories_menu_helper.rb
Delete show.html.erb
Merge pull request #19 from thangnguyendinh/category

Category
lessons
Delete users_answers_controller.rb
Delete new.html.erb
Delete show.html.erb
Merge pull request #20 from thangnguyendinh/lessons

lessons
Delete show.html.erb
Merge branch 'develop' of https://github.com/framgia/fels_16 into develop

Conflicts:
	app/controllers/lessons_controller.rb
	app/models/users_answer.rb
	app/views/lessons/new.html.erb