small modifications in sign_in spec
fix questions controller action create
fix spec for question controller
[#70182640] пользователь может создавать теги
add tag model
add specs for tags #index
add view for tags index
add feature_helper for features specs
add specs for tag model (2 not working)

add some styling to tags index view
add ability to creata tags by authentificating user

add checking tag for dublication

add specs to tags controller
change flash objects location in layout