Refine docs trigger script and use a really long branch name to test it
What does this MR do?
A couple of things:
- Truncate the branch name to avoid filesystem limitation of long names (read from https://gitlab.slack.com/archives/C16HYA2P5/p1505768026000552)
$CI_JOB_TOKENto make use of cross-project pipelines
- Use a message in case the script is used with the wrong flag