Add lint check

.github/workflows/lint.yml

@@ -0,0 +1,22 @@
+name: Lint
+
+on:
+  pull_request:
+
+jobs:
+  clippy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@master
+
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: nightly
+          override: true
+          components: clippy
+
+      - name: Run clippy
+        run: make lint