chore: Add shfmt to workflow (#231)

.github/workflows/pre-commit.yaml

@@ -9,12 +9,23 @@ jobs:
     - uses: actions/checkout@v2
     - run: |
         git fetch --no-tags --prune --depth=1 origin +refs/heads/*:refs/remotes/origin/*
+
     - name: Get changed files
       id: file_changes
       run: |
         export DIFF=$(git diff --name-only origin/${{ github.base_ref }} ${{ github.sha }})
         echo "Diff between ${{ github.base_ref }} and ${{ github.sha }}"
         echo "::set-output name=files::$( echo "$DIFF" | xargs echo )"
+
+    - name: Install shfmt
+      run: |
+        curl -L "$(curl -s https://api.github.com/repos/mvdan/sh/releases/latest | grep -o -E -m 1 "https://.+?linux_amd64")" > shfmt \
+        && chmod +x shfmt && sudo mv shfmt /usr/bin/
+    # Need to success pre-commit fix push
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+
     - uses: actions/setup-python@v2
       with:
         python-version: '3.9'