ci: Pin old werkzeug in old deps envs

Author: underyx

tox.ini

@@ -13,8 +13,10 @@ isolated_build = true
 deps =
   oldpy2deps: redis==2.6.2
   oldpy2deps: flask==0.8.0
+  oldpy2deps: werkzeug==0.8.3
   oldpy3deps: redis==2.6.2
   oldpy3deps: flask==0.11.1
+  oldpy3deps: werkzeug==0.11.15
 extras = tests
 commands = coverage run --parallel-mode -m pytest {posargs}