Added documentation

Change-Id: I4cb4c8c56642337899d0865c147b54df72b2c1fa
diff --git a/tox.ini b/tox.ini
index 75f7b62..1f4cb11 100644
--- a/tox.ini
+++ b/tox.ini
@@ -30,3 +30,9 @@
     -rmolecule/default/requirements.txt
 commands =
     molecule {posargs}
+
+[testenv:docs]
+deps =
+    -r{toxinidir}/doc/requirements.txt
+commands =
+    sphinx-build -E -W -d doc/build/doctrees -b html doc/source/ doc/build/html
\ No newline at end of file