Code and integration test for reopening needs

This has still to get more tests, but committing all available code due to holiday break.
Unit, functional, and integration tests for reopening needs
Update assertion for correct message in update need test
Remove unnecessary validation check
Bump gds-api-adapters to add reopen functionality
Remove target assignment
Use helper method for request stubbing and clarify why
Merge pull request #55 from alphagov/unmerge-needs

Unmerge needs