Update sanic

Bring back Python 3.6

Remove code on sanic < 20

Author: kigawas

.github/workflows/test.yml

@@ -5,7 +5,7 @@ on:
     branches:
       - master
     tags:
-      - 'v*.*.*'
+      - "v*.*.*"
   pull_request:
     branches:
       - master
@@ -15,58 +15,57 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ '3.6', '3.7', '3.8' ]
-        postgres-version: [ '9.6', '12.1' ]
+        python-version: ["3.6", "3.7", "3.8", "3.9"]
+        postgres-version: ["9.6", "12.1"]
     services:
       postgres:
         image: fantix/postgres-ssl:${{ matrix.postgres-version }}
         env:
           POSTGRES_USER: gino
         ports:
-        - 5432:5432
+          - 5432:5432
         # needed because the postgres container does not provide a healthcheck
         options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
     steps:
-    - name: Checkout source code
-      uses: actions/checkout@v1
-    - name: Set up Python
-      uses: actions/setup-python@v1
-      with:
-        python-version: ${{ matrix.python-version }}
-    - name: virtualenv cache
-      uses: actions/cache@preview
-      with:
-        path: ~/.cache/pypoetry/virtualenvs
-        key: ${{ runner.os }}-${{ matrix.python-version }}-poetry-${{ hashFiles(format('{0}{1}', github.workspace, '/poetry.lock')) }}
-        restore-keys: |
-          ${{ runner.os }}-${{ matrix.python-version }}-poetry-
-    - name: Install Python dependencies
-      run: |
-        curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python
-        $HOME/.poetry/bin/poetry install
-    - name: Test with pytest
-      env:
-        DB_HOST: localhost
-        DB_USER: gino
-      run: |
-        $HOME/.poetry/bin/poetry run pytest --cov=src --cov=examples --cov-fail-under=95 --cov-report xml
-    - name: Check code format with black
-      if: matrix.python-version >= '3.6'
-      run: |
+      - name: Checkout source code
+        uses: actions/checkout@v1
+      - name: Set up Python
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: virtualenv cache
+        uses: actions/cache@preview
+        with:
+          path: ~/.cache/pypoetry/virtualenvs
+          key: ${{ runner.os }}-${{ matrix.python-version }}-poetry-${{ hashFiles(format('{0}{1}', github.workspace, '/poetry.lock')) }}
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.python-version }}-poetry-
+      - name: Install Python dependencies
+        run: |
+          curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python
+          $HOME/.poetry/bin/poetry install
+      - name: Test with pytest
+        env:
+          DB_HOST: localhost
+          DB_USER: gino
+        run: |
+          $HOME/.poetry/bin/poetry run pytest --cov=src --cov=examples --cov-fail-under=95 --cov-report xml
+      - name: Check code format with black
+        run: |
           $HOME/.poetry/bin/poetry run black --check src
-    - name: Submit coverage report
-      if: matrix.python-version == '3.8' && matrix.postgres-version == '12.1' && github.ref == 'refs/heads/master'
-      env:
-        CODACY_PROJECT_TOKEN: ${{ secrets.CODACY_TOKEN }}
-      run: |
-        pip install codacy-coverage
-        python-codacy-coverage -r coverage.xml
+      - name: Submit coverage report
+        if: matrix.python-version == '3.8' && matrix.postgres-version == '12.1' && github.ref == 'refs/heads/master'
+        env:
+          CODACY_PROJECT_TOKEN: ${{ secrets.CODACY_TOKEN }}
+        run: |
+          pip install codacy-coverage
+          python-codacy-coverage -r coverage.xml
   release:
     runs-on: ubuntu-latest
     needs: test
     strategy:
       matrix:
-        python-version: [ '3.8' ]
+        python-version: ["3.8"]
     steps:
       - name: Checkout source code
         if: startsWith(github.ref, 'refs/tags/')