Add clippy GitHub Action (#4)

* Add clippy GitHub Action

* Fix up clippy workflow

Author: mattburgess

.github/workflows/clippy.yaml

@@ -0,0 +1,21 @@
+---
+name: clippy
+
+on:
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    name: clippy
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v1
+      - name: Add clippy component
+        run: rustup component add clippy
+      - name: Run clippy
+        uses: actions-rs/clippy-check@v1
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --all-features

github.tf

@@ -40,7 +40,7 @@ resource "github_branch_protection" "main" {
 
   required_status_checks {
     strict   = true
-    contexts = ["Lint"]
+    contexts = ["Lint", "clippy"]
   }
 
   required_pull_request_reviews {