added different python versions to github actions matrix

.github/workflows/lint-and-test.yml

@@ -1,10 +1,6 @@
 name: Lint & Test
 
-on:
-  push:
-    branches: [ main ]
-  pull_request:
-    branches: [ main ]
+on: [push]
 
 permissions:
   contents: read
@@ -14,39 +10,40 @@ jobs:
     strategy:
       matrix:
         django_version: [2.2, 3.0, 3.1, 3.2, 4.0a1]
+        python_version: [3.7, 3.8, 3.9, '3.10']
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v3
-    
-    - name: Set up Python 3.10
+
+    - name: Set up Python ${{ matrix.python_version }}
       uses: actions/setup-python@v3
       with:
-        python-version: "3.10"
-    
+        python-version: ${{ matrix.python_version }}
+
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
         pip install -q Django==${{ matrix.django_version }}
         pip install flake8 coverage black
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
-    
+
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names
         flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
         flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
-    
+
     - name: Lint with Black
       run: |
         black --check .
-        
+
     - name: Run tests
       run: |
         coverage3 run --source='./encrypted_fields' manage.py test
         coverage xml
-        
+
     - name: "Upload coverage to Codecov"
       uses: codecov/codecov-action@v2
       with: