b8ddb3b75f
This authentication plugin isn't grouped with the other authentication plugins, but it can be really useful for people writing proxies or implementing service-to-service calls. This commit just highlights the usefulness of this plugin with some example usecases and a code snippet. The current documentation phrases it such that it's only useful for testing. Change-Id: I1de4959ccde3fdf8141d8f4949c73542c2200483