Improve test compatibility with pytest

Also make it simpler to eventually split the single test file we currently have.

Author: saghul

.github/workflows/test.yml

@@ -24,4 +24,4 @@ jobs:
     - name: Build package
       run: python -m pip install .
     - name: Run tests
-      run: python tests/tests.py
+      run: python -m unittest -v

PYPIREADME.rst

@@ -61,16 +61,11 @@ You can force this at installation time as follows:
 Running the test suite
 ----------------------
 
-There are several ways of running the test suite:
+From the top level directory, run: ``python -m unittest -v``
 
-- Run the test with the current Python interpreter:
-
-  From the toplevel directory, run: ``python tests/tests.py``
-
-- Use Tox to run the test suite in several virtualenvs with several interpreters
-
-  From the toplevel directory, run: ``tox -e py36,py37,py38,py39`` this will run the test suite
-  on Python 3.6 through 3.9 (you'll need to have them installed beforehand)
+NOTE: Running the tests requires internet access and are somewhat environment sensitive because real DNS quesries
+are made, there is no mocking. If you observe a failure that the CI cannot reproduce, please try to setup an
+environment as close as the current CI.
 
 
 Using it from the cli, a la dig
@@ -114,7 +109,7 @@ Unless stated otherwise on-file pycares uses the MIT license, check LICENSE file
 Supported Python versions
 -------------------------
 
-Python >= 3.6 are supported. Both CPython and PyPy are supported.
+Python >= 3.7 are supported. Both CPython and PyPy are supported.
 
 
 Contributing

README.rst

@@ -67,7 +67,7 @@ You can force this at installation time as follows:
 Running the test suite
 ----------------------
 
-From the top level directory, run: ``python tests/tests.py``
+From the top level directory, run: ``python -m unittest -v``
 
 NOTE: Running the tests requires internet access and are somewhat environment sensitive because real DNS quesries
 are made, there is no mocking. If you observe a failure that the CI cannot reproduce, please try to setup an