Feature/group maintainer

Can you pull in the creds like this?  (So that it is similar to all the other usages in fedmsg projects?)

```python
creds = config['fas_credentials']

default_url = 'https://admin.fedoraproject.org/accounts/'
fasclient = fedora.client.fas2.AccountSystem(            
    base_url=creds.get('base_url', default_url),
    username=creds['username'],
    password=creds['password'],
)
```

We can re-use the same fas_credentials file from our ansible repo.