Scheduled cache updater

.github/workflows/cache-update.yml

@@ -0,0 +1,21 @@
+name: cache-update
+
+on:
+  schedule:
+    - cron: '*/30 * * * *' # every 30m for testing
+
+jobs:
+    # Cache location for arm tools
+    - name: Cache arm-none-eabi-gcc tools
+      id: cache-arm-gcc
+      uses: actions/cache@v1
+      with:
+        path: $HOME/arm-none-eabi-gcc-9-2019-q4
+        key: ${{ runner.os }}-arm-gcc-9-2019-q4
+
+    # Get the arm-non-eabi-gcc toolchain   
+    - name: Install arm-none-eabi-gcc
+      uses: fiam/arm-none-eabi-gcc@v1
+      with:
+          release: '9-2019-q4' # The arm-none-eabi-gcc release to use.
+          directory: $HOME/arm-none-eabi-gcc-9-2019-q4