Merge "Fix doc8 check"

tox.ini

@@ -25,8 +25,8 @@ commands =
 [testenv:pep8]
 commands = flake8
            # RST linter
-           doc8 --ignore-path doc/source/contributor/modules doc/source \
-           octaviaclient HACKING.rst README.rst
+           doc8 doc/source octaviaclient HACKING.rst README.rst \
+           CONTRIBUTING.rst
            # Run security linter
            {[testenv:bandit]commands}
            {toxinidir}/tools/coding-checks.sh --pylint {posargs}