Fail build on clippy

Author: indy256

.github/workflows/rust.yml

@@ -14,7 +14,7 @@ jobs:
         run: |
           cd rust
           cargo fmt -- --check
-          RUSTFLAGS="-A unused" cargo clippy
+          RUSTFLAGS="-A unused" cargo clippy -- -Dwarnings
           cargo clippy --tests
       - name: compile and test
         run: |