Send description and tag_list during registration

If specified RUNNER_DESCRIPTION or RUNNER_TAG_LIST can be send during registration. By default hostname is used for description.

We don't want user to force setting tags.

They are supplementary. If user doesn't specify tags in his jobs it will behave as usual.

What do you think about that we can deduce tag list from running environment? Something like: linux, ubuntu, centos, ubuntu-14.04. It's generally preferable to automatically have some knowledge about running env during registration.

@dzaporozhets Have a look please.

By default we would have pretty good flag set without bothering admin who is setting up runner.

Added 2 new commits:

• 609f8ed9 - Send tag_list to CI during registration
• b7963a5f - Update changelog and bump version

@vsizov Updated. Please review.

Status changed to merged

mentioned in commit 359e2fdb

Thank you @ayufan. We appreciate your efforts to make GitLab CI better.