Build GitHub Action workflow

.github/workflows/build.yml

@@ -0,0 +1,56 @@
+name: PlatformIO CI
+
+on:
+  pull_request:
+  push:
+    branches:
+        - master
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        include:
+        - os: ubuntu-latest
+          path: ~/.cache/pip
+          platformio-path: ~/.platformio
+        - os: macos-latest
+          path: ~/Library/Caches/pip
+          platformio-path: ~/Library/Caches/platformio
+        - os: windows-latest
+          path: ~\AppData\Local\pip\Cache
+          platformio-path: ~\AppData\Local\platformio\Cache
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Cache pip
+        uses: actions/cache@v3
+        with:
+          path: ${{ matrix.path }}
+          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+      - name: Cache PlatformIO
+        uses: actions/cache@v3
+        with:
+          path: ${{ matrix.platformio-path }}
+          key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.9.13"
+      - name: Install PlatformIO
+        run: |
+          python -m pip install --upgrade pip
+          pip install --upgrade platformio
+      - name: Copy of necessary files
+        run: |
+          cp platformio_orig.ini platformio.ini
+          cp src/loraconf_sample.h src/loraconf.h
+          cp src/ota_sample.conf src/ota.conf
+          cp src/paxcounter_orig.conf src/paxcounter.conf
+      - name: Run PlatformIO
+        run: pio run