Fix V3 API quota_set tests using V3 url and request

V3 tests should using V3 url. Also to make code style consistence, using
V3 HTTPRequest.

part of blueprint v3-api-unittests

Change-Id: Ief1df0bb591941cfaf9555e97bccf21fe1e56594
Merge "Fix V3 API quota_set tests using V3 url and request"