'Deletes a DB security group.
The specified DB security group must not be associated with
any DB instances.
:type db_security_group_name: string
:param db_security_group_name:
The name of the DB security group to delete.
You cannot delete the default DB security group.
Constraints:
+ Must be 1 to 255 alphanumeric characters
+ First character must be a letter
+ Cannot end with a hyphen or contain two consecutive hyphens
+ Must not be "Default"
+ May not contain spaces'

def delete_db_security_group(self, db_security_group_name):

    params = {'DBSecurityGroupName': db_security_group_name}
    return self._make_request(action='DeleteDBSecurityGroup', verb='POST', path='/', params=params)
