Update version to 8.3.2

Diff

• https://gitlab.com/gitlab-org/gitlab-qa/compare/v8.3.1...531708f4538ed7055849ef4b23f6022049eb1d47

Release notes

Fixes

• Correctly infer qa-image from development gitla... (!1025 - merged)

Checklist before merging:

• Diff link is up-to-date.
• Based on the diff, lib/gitlab/qa/version.rb is updated, according to SemVer.
• Release notes are accurate.

Checklist after merging:

• Update the release notes for the newly created tag.