Remove tox reference from contributing docs

docs/contributing.rst

@@ -83,39 +83,21 @@ The PR reviewer is a second set of eyes to see if:
 Running VCR's test suite
 ------------------------
 
-The tests are all run automatically on `Travis
-CI <https://travis-ci.org/kevin1024/vcrpy>`__, but you can also run them
-yourself using `pytest <http://pytest.org/>`__ and
-`Tox <http://tox.testrun.org/>`__.
+The tests are all run automatically on `Github Actions CI <https://github.com/kevin1024/vcrpy/actions>`__,
+but you can also run them yourself using `pytest <http://pytest.org/>`__.
 
-Tox will automatically run them in all environments VCR.py supports if they are available on your `PATH`. Alternatively you can use `tox-pyenv <https://pypi.org/project/tox-pyenv/>`_ with
-`pyenv <https://github.com/pyenv/pyenv>`_.
-We recommend you read the documentation for each and see the section further below.
-
-The test suite is pretty big and slow, but you can tell tox to only run specific tests like this::
-
-    tox -e {pyNN}-{HTTP_LIBRARY} -- <pytest flags passed through>
-
-    tox -e py38-requests -- -v -k "'test_status_code or test_gzip'"
-    tox -e py38-requests -- -v --last-failed
-
-This will run only tests that look like ``test_status_code`` or
-``test_gzip`` in the test suite, and only in the python 3.8 environment
-that has ``requests`` installed.
-
-Also, in order for the boto3 tests to run, you will need an AWS key.
+In order for the boto3 tests to run, you will need an AWS key.
 Refer to the `boto3
 documentation <https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/index.html>`__
 for how to set this up. I have marked the boto3 tests as optional in
 Travis so you don't have to worry about them failing if you submit a
 pull request.
 
-Using PyEnv with VCR's test suite
+Using Pyenv with VCR's test suite
 ---------------------------------
 
-PyEnv is a tool for managing multiple installation of python on your system.
+Pyenv is a tool for managing multiple installation of python on your system.
 See the full documentation at their `github <https://github.com/pyenv/pyenv>`_
-but we are also going to use `tox-pyenv <https://pypi.org/project/tox-pyenv/>`_
 in this example::
 
     git clone https://github.com/pyenv/pyenv ~/.pyenv
@@ -126,26 +108,21 @@ in this example::
     # Setup shim paths
     eval "$(pyenv init -)"
 
-    # Setup your local system tox tooling
-    pip3 install tox tox-pyenv
-
     # Install supported versions (at time of writing), this does not activate them
-    pyenv install 3.8.0 pypy3.8
+    pyenv install 3.12.0 pypy3.10
 
     # This activates them
-    pyenv local 3.8.0 pypy3.8
+    pyenv local 3.12.0 pypy3.10
 
     # Run the whole test suite
-    tox
-
-    # Run the whole test suite or just part of it
-    tox -e py38-requests
+    pip install .[test]
+    ./run_tests.sh
 
 
 Troubleshooting on MacOSX
 -------------------------
 
-If you have this kind of error when running tox :
+If you have this kind of error when running tests :
 
 .. code:: python