Update tox.ini

tox.ini

@@ -10,7 +10,8 @@ setenv =
 ; utf8 one, tox's env is reset. And the install of these 2 packages
 ; fail.
 whitelist_externals = /usr/bin/env
-install_command = /usr/bin/env LANG=C.UTF-8 pip install {opts} {packages}
+; TEMP, to get cache going on Travis :-/
+install_command = /usr/bin/env LANG=C.UTF-8 travis_wait pip install {opts} {packages}
 commands =
      py.test --timeout=30 --duration=10 --cov --cov-report= {posargs}
 deps =