Update the status of a build

def state(self, state):
        """Update the status of a build"""
        state = state.lower()
        if state not in valid_states:
            raise ValueError("Build state must have a value from:\n{}".format(", ".join(valid_state)))

        self.obj['state'] = state
        self.changes.append("Updating build:{}.state={}"
                            .format(self.obj['name'], state))
        return self