Fix bug when upgrading Template with new Sections ...

Section presence validation was preventing Question from being saved. This was preventing
new Sections from being saved.

Fix how section number is set

Fix bug in upgrade customization when new section ...

Adding a new section to the customized template was conflicting with the number value
on the corresponding funder template section.

Refactor how Template upgrade customization works (#1856) ...

* Refactor how Template upgrade customization works

- Added position_in_parent to child-records Phase, Section, and Questions
- Extracted upgrade_customization! into its own service object

wip: rebasing on development

wip: pushing to Ghub

wip: Template upgrade customisation service working

Add migration to update versionable_id for records

* Fix bug in org swaps test

Test was failing because JS wasn't executing fast enough in test browser

* Refactor how locales are set in specs

* Fix bug in plan exports caused by git merge

The routes weren't merged properly which seems to have caused a regression error

* Add documentation for SectionSorter

* Update rubyzip and re-instate Bundle Audit

This was disabled because it was failing the Travis CI script. Since there wasn't a
new version of the rubyzip gem to upgrade to, we couldn't turn the error off.

* Add length constraints to versionable_id

* Add length constraints to versionable_id

* Fix bug in ActsAsSortable module

... I have no idea why those issues haven't popped up before now!?

* Fix random bug in I18n

* Move versioning ID migration into own rake task