Follow-up from "Docker ci image/add dep and dependency checks jobs"

The following discussion from !1048 (merged) should be addressed:

• @tmaczukin started a discussion: (+2 comments)

  @SteveAzz One thing that I think we could add one of these two:

  1. Send a Slack notification from the dep status job to #ci_runner, when it will find that there are available updates. In best case - with a list of updates in the message content.

     It's easy. And with this, each Monday's morning (or whatever interval we'll chose) Runner maintainers would be informed about available dependency updates.

  2. Create an issue for each one dependency. If there is already an existing issue - update it to reflect current status (existing version, available version) and ping maintainers in it.

     This would be a little harder to achieve (more complicated logic) but instead of a noisy message in Slack, that can be missed or forgotten, we'd get a list of issues that could be assigned to a Milestone. With this it can became a part of our normal planning process so I think it's a better option than Slack notification (we already have too many of them)

  But we can decide about this and work on it in a separate issue/MR, leaving this as a first iteration that just adds the tests :)