add .github/workflows folder and use Python3.9

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+name: 'Continous Integration'
+
+on:
+  push:
+    branches:
+      - 'feature/**'
+      - 'bug/**'
+      - 'develop'
+      - 'release/**'
+      - 'hotfix/**'
+      - 'main'
+  pull_request:
+    branches: [ develop, main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.9'
+
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        make install
+
+    - name: Run model tests
+      run: make model-test
+
+    - name: Run API tests
+      run: make api-test

workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v2
       with:
-        python-version: '3.x'
+        python-version: '3.9'
 
     - name: Install dependencies
       run: |