Install rustup at start of CI script

.gitlab-ci.yml

@@ -15,12 +15,12 @@ variables:
   CARGO_HOME: ${CI_PROJECT_DIR}/.cargo
 
 before_script:
+  - curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --default-toolchain stable
   - rustup toolchain install nightly
 
 lint:
   stage: test
   script:
-    - rustup component add rustfmt clippy
     - cargo fmt --all --check
     - cargo clippy -- -D warnings
   cache: