Remove tox boilerplate, no longer necessary with later versions of tox.

Author: jaraco

tox.ini

@@ -1,8 +1,4 @@
 [tox]
-envlist = python
-minversion = 3.2
-# https://github.com/jaraco/skeleton/issues/6
-tox_pip_extensions_ext_venv_update = true
 toxworkdir={env:TOX_WORK_DIR:.tox}