Merge pull request #22 from alexcodreanu86/carousel

Carousel
refactored redirect to root with flash message into unauthorized_user method
added validations for pages that are only allowed to admins, or logged in users, or non users
added more responsivenes to the trip form
display information about the trip in a table
updated the routes for the trips
added booker_id to trip migration
updated the schema representation
extracted the trip form into a partial
Merge branch 'master' of http://github.com/alexcodreanu86/nitar into carousel