add lint workflow

.github/workflows/lint.yml

@@ -0,0 +1,62 @@
+name: lint
+
+on: [push, merge]
+
+jobs:
+  lint:
+    name: Run linting tools
+    runs-on: "ubuntu-latest"
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2.3.4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Python
+        uses: actions/setup-python@v2.2.2
+        with:
+          python-version: "3.9"
+
+      - name: Permacache Poetry
+        id: cache-poetry
+        uses: actions/cache@v2.1.6
+        with:
+          path: ~/.poetry
+          key: poetry
+
+      - name: Install latest version of Poetry
+        if: steps.cache-poetry.outputs.cache-hit != 'true'
+        run: |
+          curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python -
+
+      - name: Add Poetry to $PATH
+        run: |
+          echo "$HOME/.poetry/bin" >> $GITHUB_PATH
+
+      - name: Get Poetry version
+        run: poetry --version
+
+      - name: Check pyproject.toml validity
+        run: poetry check --no-interaction
+
+      - name: Cache dependencies
+        id: cache-deps
+        uses: actions/cache@v2.1.6
+        with:
+          path: ${{github.workspace}}/.venv
+          key: poetry-${{ hashFiles('**/poetry.lock') }}
+          restore-keys: poetry-
+
+      - name: Install deps
+        if: steps.cache-deps.cache-hit != 'true'
+        run: |
+          poetry config virtualenvs.in-project true
+          poetry install --no-interaction
+
+      - name: Lint code
+        run: |
+          poetry run pylint --errors-only hooks
+          poetry run flake8 hooks
+          poetry run isort --check hooks
+          poetry run black --check --diff .
+          poetry run mypy hooks