Test with PostgreSQL.

.github/workflows/python-test.yml

@@ -36,8 +36,6 @@ jobs:
             django: '>=4.1,<4.2'
           - python-version: '3.7'
             django: '>=3.2,<4.0'
-          - python-version: '3.6'
-            django: '>=3.2,<4.0'
     steps:
     - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
@@ -58,12 +56,65 @@ jobs:
       with:
         parallel: true
 
+  test_postgres_4x:
+    runs-on: ubuntu-20.04
+    services:
+      postgres:
+        image: postgres
+        env:
+          POSTGRES_PASSWORD: postgres
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 5432:5432
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ['3.8', '3.9', '3.10']
+        django: ['>=4.0,<4.1', '>=4.1,<4.2', '>=4.2,<5.0']
+        include:
+          - python-version: '3.12'
+            django: '>=4.2,<4.3'
+          - python-version: '3.11'
+            django: '>=4.2,<4.3'
+          - python-version: '3.11'
+            django: '>=4.1,<4.2'
+          - python-version: '3.7'
+            django: '>=3.2,<4.0'
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip setuptools wheel
+        python -m pip install coverage 'django${{ matrix.django }}' psycopg2cffi
+    - name: Execute tests with coverage
+      env:
+        POSTGRES_HOST: localhost
+        POSTGRES_PORT: 5432
+        PGPASSWORD: postgres
+      run: |
+        psql -c 'create database bitoptions;' -U postgres -h $POSTGRES_HOST
+        coverage run --source=bitoptions testproject/manage.py test testapp
+        coverage lcov
+        coverage report
+    - name: Coveralls
+      uses: coverallsapp/github-action@v2
+      with:
+        parallel: true
+
   test_sqlite_3x:
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9']
+        python-version: ['3.7', '3.8', '3.9']
         django: ['>=3.0,<3.1', '>=3.1,<3.2', '>=3.2,<4.0']
         include:
           - python-version: '3.10'
@@ -90,7 +141,7 @@ jobs:
 
   generate-coverage-report:
     runs-on: ubuntu-latest
-    needs: [test_sqlite_4x, test_sqlite_3x]
+    needs: [test_sqlite_4x, test_sqlite_3x, test_postgres_4x]
     steps:
       - name: Coveralls
         uses: coverallsapp/github-action@v2