Added github workflow actions.

Triggers the workflow on push or pull-request events.

Do not use pip caching since it looks for a requirement.txt file that does
not exist.

.github/workflows/run_tests.yml

@@ -0,0 +1,32 @@
+# GitHub actions workflow for testing pylint-silent.
+
+name: run tests
+
+# Triggers the workflow on push or pull-request events.
+on: [push, pull_request]
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        # Run on earliest and latest supported python versions.
+        python-version: ["3.7", "3.11"]
+        # Run linters and pytests.
+        testsuite: ["linters", "pytest"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: install pip and tox
+        run: |
+          python -m pip install --upgrade pip
+          pip install tox
+      - name: run linters
+        # Linters are only run on the earliest supported python version.
+        if: ${{ matrix.python-version == '3.7' && matrix.testsuite == 'linters' }}
+        run: tox -e py3-pytest
+      - name: run pytest
+        if: ${{ matrix.testsuite == 'pytest' }}
+        run: tox -e mypy,pep8,pylint