WIP: Resolve "make CI faster by using a docker image with pre-compiled clippy"

Closes #49 (closed)

.gitlab-ci.yml

@@ -43,12 +43,11 @@ build_and_tests:nightly:
   
 clippy:
   stage: clippy
-  image: rustlang/rust:nightly
+  image: tomastomecek/rust:clippy
   tags:
     - redshift-rs-nightly
   before_script:
     - export PATH="$HOME/.cargo/bin:$PATH"
-    - cargo install --force clippy --verbose
   script:
     - cargo clippy --all -- -D warnings --verbose
   allow_failure: true