Fix the fas_login_required decorator

The redirection to login is a bad idea has if the user is already logged in there,
fas-openid will redirect to nuancier which will redirect to fas-openid, creating an infinite
loop of redirection.

This commit should fix it.

Fixes #11
Add check for CLA  done (signed)
Merge pull request #16 from fedora-infra/fix_login_decorator

Fix the fas_login_required decorator