add schema info in users model
wrong log out. I intend to logout with facebook, however this code works logout from facebook.
add Koala gem for using facebook api in Ruby and put gems in order a bit.
install Koala
create user with facebook uid.
login button is working.
writing spec
Test for user register is written.
Test for user sign-in  who has been registered.
add attribute remember_token for session controll
resolce conflicts