Update spring to 1.7.2 to fix hanging rails console

What does this MR do?

Update spring to 1.7.2.

Why was this MR needed?

This fixes hanging rails console issue.

Related

Fixes https://gitlab.com/gitlab-org/gitlab-development-kit/issues/127

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together