update tox to only use default python version

Author: dhellmann

docs/source/developers.rst

@@ -69,22 +69,24 @@ The test suite for virtualenvwrapper uses shunit2_ and tox_.  The
 shunit2 source is included in the ``tests`` directory, but tox must be
 installed separately (``pip install tox``).
 
-To run the tests under bash, zsh, and ksh for Python 2.7 through 3.6,
-run ``tox`` from the top level directory of the hg repository.
+To run the tests under bash and zsh for the default Python,
+run ``tox`` from the top level directory of the hg repository::
+
+  $ tox
 
 To run individual test scripts, use a command like::
 
-  $ tox tests/test_cd.sh
+  $ tox -- tests/test_cd.sh
 
 To run tests under a single version of Python, specify the appropriate
 environment when running tox::
 
-  $ tox -e py27
+  $ tox -e py311
 
 Combine the two modes to run specific tests with a single version of
 Python::
 
-  $ tox -e py27 tests/test_cd.sh
+  $ tox -e py311 -- tests/test_cd.sh
 
 To stop the test suite as soon as any test fails, use the `fast` tox
 target::

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py33,py34,py35,py36,zsh,ksh,style
+envlist = py,zsh,style
 
 [testenv]
 install_command = pip install -U {opts} {packages}