Does not authenticate to the database

[ebaratte]

If the database to profile does not allow unauthenticated requests, every command will fail (and professor will return a 500 error without explanation)

I guess we should add a line in util.py, for the connect_to method:

def connect_to(database, username, password):
    # [...]
    conndb = conn[database['dbname']]
    conndb.authenticate(username, password)
    return conndb