Test with CH 21.3 and 20.8

.github/workflows/python-package.yml

@@ -30,17 +30,16 @@ jobs:
         poetry install
     - name: Lint with flake8
       run: |
-        poetry run flake8 clickhouse_orm/
-        cd tests && poetry run flake8
+        poetry run flake8
     - name: Check formatting with black
       run: |
-        poetry run black --line-length 120 --check clickhouse_orm/ tests/
+        poetry run black --check .
 
   test:
     runs-on: ubuntu-latest
     services:
       clickhouse:
-        image: yandex/clickhouse-server:20.8
+        image: yandex/clickhouse-server:21.3
         ports:
           - 8123:8123
     strategy:
@@ -61,3 +60,30 @@ jobs:
     - name: Test with pytest
       run: |
         poetry run pytest
+
+  test_compat:
+    # Tests compatibility with an older LTS release of clickhouse
+    runs-on: ubuntu-latest
+    services:
+      clickhouse:
+        image: yandex/clickhouse-server:20.8
+        ports:
+          - 8123:8123
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: [3.9]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install poetry
+        poetry install
+    - name: Test with pytest
+      run: |
+        poetry run pytest