Update django.yml

.github/workflows/django.yml

@@ -10,20 +10,16 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
-    strategy:
-      max-parallel: 4
-      matrix:
-        python-version: [3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python ${{ matrix.python-version }}
+    - name: Set up Python 3.7
       uses: actions/setup-python@v3
       with:
-        python-version: ${{ matrix.python-version }}
+        python-version: 3.7
     - name: Install Dependencies
       run: |
-        python -m pip install --upgrade pip
+        python3 -m pip install --upgrade pip
         pip install -r requirements.txt
     - name: Run Tests
       run: |