fix: Set up python3 (CI process)

Author: fabidick22

.github/workflows/CI-pipeline.yml

@@ -10,6 +10,10 @@ jobs:
       - name: Checkout
         uses: actions/checkout@master
 
+      - uses: actions/setup-python@v2
+        with:
+          python-version: '3.7.x'
+
       - name: Install AWS SAM
         run: pip install aws-sam-cli