Try a workaround for the reactor_option error

Author: altendky

tox.ini

@@ -16,10 +16,9 @@ deps=
     qt5reactor: qt5reactor
     qt5reactor: pytest-xvfb
     qt5reactor: pyqt5
-setenv=
-    defaultreactor: reactor_option=default
-    qt5reactor: reactor_option=qt5reactor
-commands=py.test --reactor={env:reactor_option} []
+commands=
+    defaultreactor: py.test --reactor=default []
+    qt5reactor: py.test --reactor=qt5reactor []
 sitepackages=False
 
 [testenv:linting]