CI: add timeout support to gitlab_test_helper class

What does this MR do?

CI: add timeout support to gitlab_test_helper class

Add support for specifying timeouts to gitlab_test_helper class, via the use of duration formats. These can be specified by environment variables.

• Default: '2m'
• Scale variable 'KUBE_SCALE_TIMEOUT'
• Rollout variable ' KUBE_ROLLOUT_TIMEOUT'

These apply to the kubectl command that they would be used for.

Example: In order to wait 5 minutes for kubectl rollout to complete, set KUBE_ROLLOUT_TIMEOUT to 5m or 300s.

Ruby Gem Addition: https://github.com/floraison/fugit

This adds fugit gem, which provides support for parsing many formats of time / cron / duration. It can be used for many other things in RSpec, now that it is present.

Related issues

Author checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• When ready for review, follow the instructions in the "Reviewer Roulette" section of the Danger Bot MR comment, as per the Distribution experimental MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added/updated
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened
• Equivalent MR/issue for Gitlab Operator project opened (see Operator documentation on impact of Charts changes)
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.