Fix tests running for zuul

- Add Sphinx to test-requirements
- Add a venv environment to tox for zuul runner.
- Fix pep8 issue in tests.

Change-Id: I742802381e588790a86d00371829dc88d21c9e64

requests_mock/tests/test_matcher.py

@@ -12,8 +12,6 @@
 
 import re
 
-import requests
-
 from requests_mock import adapter
 from requests_mock.tests import base
 

test-requirements.txt

@@ -1,5 +1,6 @@
 discover
 fixtures
 mock
+sphinx>=1.1.2,!=1.2.0,<1.3
 testrepository>=0.0.18
 testtools

tox.ini

@@ -15,6 +15,9 @@ deps =
     flake8
     {[testenv]deps}
 
+[testenv:venv]
+commands = {posargs}
+
 [testenv:coverage]
 commands =
     coverage erase