ci: run clippy

.gitlab-ci.yml

@@ -2,6 +2,7 @@ image: "rust:latest"
 
 stages:
   - test
+  - lint
 
 variables:
   CARGO_HOME: "${CI_PROJECT_DIR}/.cargo"
@@ -19,3 +20,10 @@ test:
   script:
     - cargo build --release --locked
     - cargo test --release --locked
+
+lint:
+  stage: lint
+  before_script:
+    - rustup component add clippy
+  script:
+    - cargo clippy --all -- -D warnings