Return True / False on authentication success.

    PyMongo 2.6 changed the auth API to raise on Auth failure.

def authenticate(db, user, password):
    """
    Return True / False on authentication success.

    PyMongo 2.6 changed the auth API to raise on Auth failure.
    """
    try:
        logger.debug("Authenticating {} with {}".format(db, user))
        return db.authenticate(user, password)
    except OperationFailure as e:
        logger.debug("Auth Error %s" % e)
    return False