Lint shell scripts with shellcheck

Author: matthewfeickert

.github/workflows/ci.yml

@@ -22,6 +22,10 @@ jobs:
       uses: actions/setup-python@v1
       with:
         python-version: ${{ matrix.python-version }}
+    - name: Install utilities
+      run: |
+        apt-get -qq -y update
+        apt-get -qq -y install shellcheck
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip setuptools wheel
@@ -35,6 +39,11 @@ jobs:
       if: matrix.python-version == 3.7 && matrix.os == 'ubuntu-latest'
       run: |
         black --check --diff --verbose .
+    - name: Lint with Shellcheck
+      if: matrix.python-version == 3.7 && matrix.os == 'ubuntu-latest'
+      run: |
+        shellcheck tests/*.sh
+        shellcheck scripts/*.sh
     - name: Check MANIFEST
       if: matrix.python-version == 3.7 && matrix.os == 'ubuntu-latest'
       run: |