Add: GitHub action on pull request to main

.github/workflows/run-tests.yaml

@@ -0,0 +1,25 @@
+name: Unit and System Tests
+
+on:
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python 3.11
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.11
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r requirements.txt
+    - name: Run pytest
+      run: |
+        pytest --cov=src --cov-fail-under=95 -m "unit and not slow or system"