Add GHAs.

Author: thejpster

.github/workflows/build.yml

@@ -0,0 +1,16 @@
+name: Build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+      with:
+        submodules: true
+    - name: Add Target
+      run: rustup target add thumbv6m-none-eabi
+    - name: Build
+      run: cargo build --verbose --target=thumbv6m-none-eabi

.github/workflows/format.yml

@@ -0,0 +1,13 @@
+name: Format
+
+on: [push, pull_request]
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Add Tool
+      run: rustup component add rustfmt
+    - name: Check Format
+      run: cargo fmt -- --check