Add linting action

Author: basilfx

.github/workflows/lint.yml

@@ -0,0 +1,45 @@
+name: Linting
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-python@v2
+        with:
+          python-version: "3.10"
+
+      - uses: actions/cache@v2
+        with:
+          path: ~/.local
+          key: poetry-1.2.2
+
+      - uses: snok/install-poetry@v1
+        with:
+          version: 1.2.2
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+
+      - uses: actions/cache@v2
+        id: cache-deps
+        with:
+          path: .venv
+          key: pydeps-${{ hashFiles('**/poetry.lock') }}
+
+      - run: poetry install --no-interaction --no-root
+        if: steps.cache-deps.outputs.cache-hit != 'true'
+
+      - run: poetry install --no-interaction
+
+      - run: poetry run flake8 tinylink tests
+
+      - run: poetry run black --check --diff tinylink tests
+
+      - run: poetry run isort --check --diff tinylink tests