Gh build (#1)

* add automated build

.github/workflows/build-raspi.yaml

@@ -0,0 +1,14 @@
+name: Build It
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Build for Raspberry Pi 2/3/4 32 bit
+      uses: actions-rs/cargo@v1
+      with:
+        use-cross: true
+        command: build
+        args: --target armv7-unknown-linux-gnueabihf