feat: Update GitHub Actions workflow for Python testing

fix: Replace Unittest with Unittest discover command
patch: Remove deprecated tests.py file

Author: Simatwa

.github/workflows/python-test.yml

@@ -1,7 +1,7 @@
 # This workflow will install Python dependencies, run tests and lint with a variety of Python versions
 # For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-python
 
-name: Python package
+name: Unit Test
 
 on:
   push:
@@ -36,4 +36,4 @@ jobs:
         flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with Unittest
       run: |
-        python -m tests.py -fv
+        python -m unittest discover -s tests -p 'test_*.py' -f -v