Disallow clippy warnings

Author: onethumb

.github/workflows/tests.yml

@@ -33,7 +33,7 @@ jobs:
         run: cargo fmt -- --check
       - if: ${{ matrix.rust-toolchain != 'nightly' }}
         name: Clippy
-        run: cargo clippy
+        run: cargo clippy -- -D warnings
       - name: Test
         run: cargo test
 
@@ -64,7 +64,7 @@ jobs:
         run: cargo fmt -- --check
       - if: ${{ matrix.rust-toolchain != 'nightly' }}
         name: Clippy
-        run: cargo clippy
+        run: cargo clippy -- -D warnings
       - name: Test
         run: cargo test