Update .gitlab-ci.yml

.gitlab-ci.yml

-#image: ubuntu:latest
-build:latest:
-    image: ubuntu:latest
-    script:
-    - apt update
-    - apt install -y sudo git g++ cmake ninja-build
-    - developer_tools/clone_standard_modules.sh
-    - ./install.sh all 
-    - ./check_all.sh
-    - developer_tools/update_bash_profile.sh ~/.bashrc
-    - source ~/.bashrc
-build:xenial:
-    image: ubuntu:xenial
+.install_script: &install_definition
     script:
         - apt update
         - apt install -y wget sudo
-        - wget -O - https://git.u-cergy.fr/blaar/blaar/raw/master/developer_tools/clone_and_install_blaar_ubuntu.sh | bash
\ No newline at end of file
+        - wget -O - https://git.u-cergy.fr/blaar/blaar/raw/master/developer_tools/clone_and_install_blaar_ubuntu.sh | bash
+
+build:xenial:
+    image: ubuntu:xenial
+    <<: *install_definition
+
+build:latest:
+    image: ubuntu:latest
+    <<: *install_definition
\ No newline at end of file