Remove tox locale overrides

* tox.ini: The LANG, LANGUAGE and LC_ALL environment overrides were
introduced originally during the testr migration in an attempt to be
conservative about the possibility that locale settings in the
calling environment could cause consistency problems for test runs.
In actuality, this should be unnecessary and any place where it does
cause issues ought to be considered an actual bug. Also, having
these in the configuration actively causes older pip to have
problems with non-ASCII content in some package metadata files under
Python 3, so drop it now.

Change-Id: I0661b20a0e426fee56bc706d364dfe158da9be72
Closes-Bug: #1277495
Remove unused mock in v2/test_shell.py

Change-Id: Ia2dd362bf30b527145635b1afd9c10bd0c2556b7
Merge "Remove unused mock in v2/test_shell.py"
Merge "Remove tox locale overrides"