Add gateway in network_info and share network API

Get gateway information from network plugin and put it into network_info.
It is required by EMC Unity storage to create a interface.

APIImpact
DocImpact

Change-Id: I8614b8686af7fa5764b49e8e3cb4a4855dc3a5f4
Implements: blueprint add-gateway-info
3 files changed
tree: aabc8321391a46e656f210e4debc92f434628cd1
  1. manila_tempest_tests/