Add clippy to CI

Author: datapythonista

.github/workflows/main.yml

@@ -16,3 +16,12 @@ jobs:
         run: cargo install cargo-deb
       - name: Package .deb
         run: cargo deb
+  check:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Update rustup
+        run: rustup update
+      - name: Clippy
+        run: cargo clippy -- -Dwarnings