Create github workflow lint.yml (#8)

.github/workflows/lint.yml

@@ -0,0 +1,45 @@
+name: Lint
+
+on:
+  push:
+    branches:
+    - main
+  pull_request:
+
+jobs:
+  flake8-py3:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup Python
+        uses: actions/setup-python@v1
+        with:
+          python-version: 3.x
+          architecture: x64
+      - name: Fetch Wenet
+        uses: actions/checkout@v1
+      - name: Checkout PR tip
+        run: |
+          set -eux
+          if [[ "${{ github.event_name }}" == "pull_request" ]]; then
+            # We are on a PR, so actions/checkout leaves us on a merge commit.
+            # Check out the actual tip of the branch.
+            git checkout ${{ github.event.pull_request.head.sha }}
+          fi
+          echo ::set-output name=commit_sha::$(git rev-parse HEAD)
+        id: get_pr_tip
+      - name: Run flake8
+        run: |
+          set -eux
+          pip install flake8==3.8.2 flake8-bugbear flake8-comprehensions flake8-executable flake8-pyi==20.5.0 mccabe pycodestyle==2.6.0 pyflakes==2.2.0
+          flake8 --version
+          flake8 | tee ${GITHUB_WORKSPACE}/flake8-output.txt
+      - name: Add annotations
+        uses: pytorch/add-annotations-github-action@master
+        with:
+          check_name: 'flake8-py3'
+          linter_output_path: 'flake8-output.txt'
+          commit_sha: ${{ steps.get_pr_tip.outputs.commit_sha }}
+          regex: '^(?<filename>.*?):(?<lineNumber>\d+):(?<columnNumber>\d+): (?<errorCode>\w\d+) (?<errorDesc>.*)'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+