Update .gitlab-ci.yml: cmake added

.gitlab-ci.yml

@@ -10,12 +10,11 @@ build:
   stage: build
   tags: 
     - gcc
-  # instead of calling g++ directly you can also use some build toolkit like make
-  # install the necessary build tools when needed
   before_script: 
-    - apt update && apt -y install libreadline-dev 
+    - apt update && apt -y install libreadline-dev cmake
   script:
-    - gcc lw12.c lw12ctl.c -o lw12ctl
+    - cmake .
+    - make
   artifacts:
     paths:
       - lw12ctl