Remove last reference to setup.py

Author: ichard26

tox.ini

@@ -13,7 +13,6 @@ deps =
 commands =
     sphinx-build -W -b html -d {envtmpdir}/doctrees docs docs/_build/html
     sphinx-build -W -b doctest -d {envtmpdir}/doctrees docs docs/_build/html
-    python setup.py check -m -r -s
 
 [testenv:mypy]
 deps = mypy