update changelog and doc

Author: bagerard

CONTRIBUTING.rst

@@ -82,7 +82,7 @@ General Guidelines
   should adapt to the breaking change in docs/upgrade.rst.
 - Write inline documentation for new classes and methods.
 - Write tests and make sure they pass (make sure you have a mongod
-  running on the default port, then execute ``python setup.py test``
+  running on the default port, then execute ``pytest tests/``
   from the cmd line to run the test suite).
 - Ensure tests pass on all supported Python, PyMongo, and MongoDB versions.
   You can test various Python and PyMongo versions locally by executing

README.rst

@@ -125,8 +125,7 @@ Some simple examples of what MongoEngine code looks like:
 Tests
 =====
 To run the test suite, ensure you are running a local instance of MongoDB on
-the standard port and have ``pytest`` installed. Then, run ``python setup.py test``
-or simply ``pytest``.
+the standard port and have ``pytest`` installed. Then, run ``pytest tests/``.
 
 To run the test suite on every supported Python and PyMongo version, you can
 use ``tox``. You'll need to make sure you have each supported Python version
@@ -139,15 +138,6 @@ installed in your environment and then:
     # Run the test suites
     $ tox
 
-If you wish to run a subset of tests, use the pytest convention:
-
-.. code-block:: shell
-
-    # Run all the tests in a particular test file
-    $ pytest tests/fields/test_fields.py
-    # Run only particular test class in that file
-    $ pytest tests/fields/test_fields.py::TestField
-
 Community
 =========
 - `MongoEngine Users mailing list

docs/changelog.rst

@@ -7,6 +7,7 @@ Changelog
 Development
 ===========
 - (Fill this out as you fix issues and develop your features).
+- Switch tox to use pytest instead of legacy `python setup.py test` #2804
 
 Changes in 0.28.2
 =================