Deprecated GitLab CI/CD variables

GitLab 9.0 renamed variables

To follow conventions of naming across GitLab, and to further move away from the build term and toward job, some CI/CD environment variables were renamed for GitLab 9.0 release.

NOTE: Note: Starting with GitLab 9.0, we have deprecated the $CI_BUILD_* variables. You are strongly advised to use the new variables as we will remove the old ones in future GitLab releases.

8.x name	9.0+ name
`CI_BUILD_ID`	`CI_JOB_ID`
`CI_BUILD_REF`	`CI_COMMIT_SHA`
`CI_BUILD_TAG`	`CI_COMMIT_TAG`
`CI_BUILD_BEFORE_SHA`	`CI_COMMIT_BEFORE_SHA`
`CI_BUILD_REF_NAME`	`CI_COMMIT_REF_NAME`
`CI_BUILD_REF_SLUG`	`CI_COMMIT_REF_SLUG`
`CI_BUILD_NAME`	`CI_JOB_NAME`
`CI_BUILD_STAGE`	`CI_JOB_STAGE`
`CI_BUILD_REPO`	`CI_REPOSITORY_URL`
`CI_BUILD_TRIGGERED`	`CI_PIPELINE_TRIGGERED`
`CI_BUILD_MANUAL`	`CI_JOB_MANUAL`
`CI_BUILD_TOKEN`	`CI_JOB_TOKEN`