[skeleton] drop whitelist_externals for flake8
whitelist_externals makes sense when used with sitepackages=true.
In this case it will always rely on $VIRTUAL_ENV/bin/flake8 so, the
whitelist_externals has no effect.
--- a/cubicweb/skeleton/tox.ini.tmpl Mon Oct 29 16:39:21 2018 +0100
+++ b/cubicweb/skeleton/tox.ini.tmpl Tue Jan 29 14:02:19 2019 +0100
@@ -9,8 +9,6 @@
[testenv:flake8]
skip_install = true
-whitelist_externals =
- flake8
deps =
flake8
commands = flake8