In the current implementation, when the TaaS API (tap-service,
tap-flow) call completes, the status of result is returned. [1]
In order to adopt an asynchronous model, the 'status' field is
needed in the API.
The following code adds the status field in the API.
In the first step, the status is set to 'ACTIVE' by default.
[1]: http://lists.openstack.org/pipermail/openstack-dev/2016-March/090088.html
Depends-On: Ie6b3811e41a94721679c9178cdd5119bdad8208d
Change-Id: Ib8e4ad15e5b4272ac7f8800f72d7f2c003db798e
752fb029fa