[feature/users-management] user model with password and profil page
[feature/users-management] user signup
[feature/users-management] add flash message after user signed up
[feature/users-management] signin and signout
Merge branch 'frontend' into feature/users-management

Conflicts:
	app/views/users/show.html.erb
[users-management] signin and signet in views
Fix js use with turbolink