Create a role

def create(self, handle, title=None, description=None):
        """ Create a role """
        role = Role(handle=handle, title=title, description=description)
        schema = RoleSchema()
        valid = schema.process(role)
        if not valid:
            return valid

        db.session.add(role)
        db.session.commit()

        events.role_created_event.send(role)
        return role