refractored signin form
added thin to gemfile
added test of the edit page for a link with the url containing gravatar images
defined edit function in users controller to get alias to a specific user identified by their id
added edit view for editing user profile
added edit view for editing user profile
added test for Settings link which is dependent on sign in status of the user
added settings link to header of application layout
added update user action test
added update action to users controller
added authorization check for patch request to authentication spec test
added before_action signed in user check to edit and update action only in user controller
added wrong user patch request test in authorization
added wrong user patch request test in users controller
added check for friendly forwarding(directing to intended page after sign in)
implement friendly forwarding in session controller
added test for visiting user index page by non sign in user
implemented check for user signed_in status when visit index page
added test + implemented index page
added index view + css