added new sessions controller
added integration test for authentication machinery
added new routes for session controlling and new methods to the session controller
added remember token to user model. added test for remember token to user model tests
added bootstrap js lib. auto sign_in after creating new account. and some tests
added check for logout link
moved some spec to the correct spec file. fixed an error regarding signout route
moved test from nvalid to valid part
finish sign in and out