Adjust the default tox invocation

Author: dmtucker

tox.ini

@@ -80,7 +80,7 @@ deps =
 
     pytest-cov ~= 2.5.1
     pytest-randomly ~= 2.1.1
-commands = py.test -p no:mypy -n auto --cov pytest_mypy --cov-fail-under 100 --cov-report term-missing {posargs}
+commands = py.test -p no:mypy --cov pytest_mypy --cov-fail-under 100 --cov-report term-missing {posargs:-n auto} tests
 
 [testenv:static]
 deps =