https://github.com/gsnedders/wcag-contrast-ratio/issues/7

--- wcag-contrast-ratio-0.9/tox.ini.orig
+++ wcag-contrast-ratio-0.9/tox.ini
@@ -4,7 +4,7 @@
 [testenv]
 deps =
   pytest
-  hypothesis-pytest
+  hypothesis
 
 commands =
   {envbindir}/py.test test.py