👷 Add caching to CI workflow

.github/workflows/test-builds.yml

@@ -107,8 +107,25 @@ jobs:
 
  steps:
 
+ - name: Check out the PR
+ uses: actions/checkout@v2
+
+ - name: Cache pip
+ uses: actions/cache@v2
+ with:
+ path: ~/.cache/pip
+ key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+ restore-keys: |
+ ${{ runner.os }}-pip-
+
+ - name: Cache PlatformIO
+ uses: actions/cache@v2
+ with:
+ path: ~/.platformio
+ key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
+
  - name: Select Python 3.7
- uses: actions/setup-python@v1
+ uses: actions/setup-python@v2
  with:
  python-version: '3.7' # Version range or exact version of a Python version to use, using semvers version range syntax.
  architecture: 'x64' # optional x64 or x86. Defaults to x64 if not specified
@@ -118,9 +135,6 @@ jobs:
  pip install -U https://github.com/platformio/platformio-core/archive/develop.zip
  platformio update
 
- - name: Check out the PR
- uses: actions/checkout@v2
-
  - name: Run ${{ matrix.test-platform }} Tests
  run: |
  make tests-single-ci TEST_TARGET=${{ matrix.test-platform }}