Enable neutronclient OSC plugin support.
This patch set does the following:
- Establishes OSC plugin structure for commands and unit tests
- Creates the OSC plugin
- Adds OSC to test-requirements.txt
Co-Authored-By: Akihiro Motoki <motoki@da.jp.nec.com>
Change-Id: I9a20bc7a3d8aa7b631fb0fd534fc5705c23326ce
Related-Bug: #1521291