Gitlab CI/CD settings configuration.

[edelfour]

Add the possibility to set variables for CI/CD on level project.

Variables can be configured through gitlab_ci_variables parameter.
Example:

gitlab_ci_variables:
    - name: SERVER_NAME
       value: myServer
    - name: USERNAME
       value: user1

By default, untouched variable will be kept. To remove them, set purge_gitlab_ci_variables parameter to true