remove old optional in file requirement

tox.ini

@@ -25,9 +25,7 @@ commands = pytest {posargs}
 [testenv:unpinned]
 description = Test with unpinned dependencies, as a user would install now.
 deps =
-  -r requirements/basetest.txt
-  -r requirements/base.in
-  -r requirements/optional.in
+  -r requirements/basetest.in
   plopp
 commands = pytest {posargs}