colour the footer links to match
Add authentication through devise

We now:
a) have users
b) can sign up/register as a user
c) can login/logout
d) can see your login/logout status with relevant links
e) must login to get to any of the creaty/edity actions
(you can see and list venues and get to the welcome page).
You are automatically redirected to login pages if you try to access these
actions - and get redirected back again when done.
f) tests have been updated to reflect the above