Use Python 2.7 for mkdocs build.

carltongibson · carltongibson · commit 1950896e9fce · 2019-04-29T22:31:09.000+02:00
diff --git a/tox.ini b/tox.ini
@@ -51,7 +51,7 @@ deps =
         -rrequirements/requirements-testing.txt
 
 [testenv:docs]
-basepython = python3.7
+basepython = python2.7
 commands = mkdocs build
 deps =
        -rrequirements/requirements-testing.txt
