Added git workflow and shell script for fuzzing

.github/workflows/cargo_fuzz.yml

@@ -0,0 +1,32 @@
+---
+name: Cargo fuzz build
+on:
+  push:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  build_fuzzing:
+    strategy:
+      matrix:
+        os: [ubuntu-18.04, macos-10.15]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: "true"
+      - uses: actions-rs/toolchain@v1
+        with:
+          target: thumbv7em-none-eabi
+      - uses: actions/setup-python@v1
+        with:
+          python-version: 3.7
+      - name: Install Python dependencies
+        run: python -m pip install --upgrade pip setuptools wheel
+      - name: Set up OpenSK
+        run: ./setup.sh
+      - name: Set up fuzzing
+        run: ./fuzzing_setup.sh
+
+      - name: Cargo fuzz build
+        run: cargo fuzz build