Merge "Add doc8 tox env"

tox.ini

@@ -32,6 +32,13 @@ downloadcache = ~/cache/pip
 sitepackages = False
 commands = flake8
 
+[testenv:doc8]
+deps =
+    -r{toxinidir}/requirements.txt
+    -r{toxinidir}/test-requirements.txt
+    doc8
+commands = doc8 doc/source
+
 [testenv:venv]
 commands = {posargs}