fix linting and updating maintenance guide

Updating the maintainers guide with updated intructions from
Ansible engineers.

Fixing linting issues, and adding the linter as a GitHub workflow
to ensure there are no regressions.

.github/workflows/ansible-test.yml

@@ -1,34 +1,35 @@
 name: "Run tests for the cloud.google collection"
 on: [pull_request]
+env:
+  PYTHON_VERSION: "3.9" # minimum version for Ansible 2.14
 jobs:
-  # sanity tests cannot be turned on until #498 is resolved.
-  # sanity:
-  #   runs-on: ubuntu-latest
-  #   defaults:
-  #     run:
-  #       working-directory: ansible_collections/google/cloud
-  #   strategy:
-  #     matrix:
-  #       ansible_version:
-  #         - stable-2.13
-  #         - stable-2.11
-  #   steps:
-  #     - name: check out code
-  #       uses: actions/checkout@v2
-  #       with:
-  #         path: ansible_collections/google/cloud
-  #     - name: Set up Python
-  #       uses: actions/setup-python@v1
-  #       with:
-  #         python-version: '3.8'  # this is the minimum version required for Ansible 2.11
-  #     - name: Install ansible-base (${{ matrix.ansible_version }})
-  #       uses: nick-invision/retry@v2
-  #       with:
-  #         timeout_minutes: 3
-  #         max_attempts: 3
-  #         command: pip install https://github.com/ansible/ansible/archive/${{ matrix.ansible_version }}.tar.gz --disable-pip-version-check
-  #     - name: Run sanity tests
-  #       run: ansible-test sanity --docker -v --color --python 3.8
+  sanity:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ansible_collections/google/cloud
+    strategy:
+      matrix:
+        ansible_version:
+          - stable-2.14
+    steps:
+      - name: check out code
+        uses: actions/checkout@v2
+        with:
+          path: ansible_collections/google/cloud
+      - name: Set up Python
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+      - name: Install ansible-base (${{ matrix.ansible_version }})
+        uses: nick-invision/retry@v2
+        with:
+          timeout_minutes: 3
+          max_attempts: 3
+          command: pip install https://github.com/ansible/ansible/archive/${{ matrix.ansible_version }}.tar.gz --disable-pip-version-check
+      - name: Run sanity tests
+        # validate-modules cannot be turned on until #498 is resolved.
+        run: ansible-test sanity -v --color --python "$PYTHON_VERSION" --skip validate-modules
   unit:
     runs-on: ubuntu-latest
     defaults:
@@ -47,7 +48,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v1
         with:
-          python-version: '3.9'  # this is the minimum version required for Ansible 2.14
+          python-version: ${{ env.PYTHON_VERSION }}
       - name: Install dependencies
         run: pip install -r requirements.txt
       - name: Install test dependencies
@@ -55,4 +56,4 @@ jobs:
       - name: Install ansible-base (${{ matrix.ansible_version }})
         run: pip install https://github.com/ansible/ansible/archive/${{ matrix.ansible_version }}.tar.gz --disable-pip-version-check
       - name: Run unit tests
-        run: ansible-test units -v --color --python 3.9
+        run: ansible-test units -v --color --python "$PYTHON_VERSION"