Change 'revision' to 'revision_number'
Change 'revision' to 'revision_number'

Neutron have changed the API[1], and changed the key name from
'revision' to 'revision_number'. This patch attempts to change
Dragonflow API usage.

[1] https://review.openstack.org/#/c/365183/

Change-Id: Ib484eb9d0e7b220d5282728e8cf4496cc526a6a9

openstack/dragonflow,openstack/dragonflow,openstack/dragonflow