Update Python version used to 3.8

Update actions/checkout to v2
Update formatting to match downstream children

.github/workflows/build.yml

@@ -10,20 +10,16 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
-
-      - name: Set up Python 3.7
-        uses: actions/setup-python@v1
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v1
         with:
-          python-version: 3.7
-
+          python-version: 3.8
       - name: Cache pre-commit hooks
         uses: actions/cache@v1
         with:
           path: ~/.cache/pre-commit
           key: "${{ runner.os }}-pre-commit-\
             ${{ hashFiles('**/.pre-commit-config.yaml') }}"
-
       - name: Cache pip test requirements
         uses: actions/cache@v1
         with:
@@ -33,11 +29,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-pip-test-
             ${{ runner.os }}-pip-
-
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
           pip install --upgrade -r requirements-test.txt
-
       - name: Run pre-commit on all files
         run: pre-commit run --all-files