Correctly generate change notes from publication log

When a manual and its documents are published, we create a
PublicationLog entry -- one for each document, each time the manual is
published. This is then used to generate the change notes.

However, we only want to generate a change note for a document for the
first PublicationLog entry for each document version.

Filter out only the appropriate entries.
Remove all PublicationLog's from production

At the time of writing (and for the forseeable future...) there are no
published manuals on production.

However, there are a couple of manuals that have been accidentally
published and manually unpublished, which has generated PublicationLog
entries.

Given that we've now changed the format of PublicationLog, adding a
version_number, and we'd like all PublicationLogs to include this piece
of information, destroy all existing ones so that when manuals are
published for real, all PublicationLogs will conform to the expected
schema.
Merge pull request #213 from alphagov/correctly-generate-change-notes

Correctly generate change notes from publication log
publish-a-manual.feature: fix typo, fix branding
Merge pull request #214 from alphagov/fix-typo-in-pulishing-a-manual-feature

publish-a-manual.feature: fix typo, fix branding
Bump gds-api-adapters to 14.1.0

This picks up the adapter for the Publishing API.
Merge pull request #215 from alphagov/bump-gds-api-adapters

Bump gds-api-adapters to 14.1.0
Remove final remnants of service registry

This lets us clean up any mention of services from the wiring, and
remove ManualDocumentAttachment and ManualDocument services into their
own registries, per others.
Merge pull request #216 from alphagov/remove-service-registry

Remove final remnants of service registry
Create class for manual builder
Manual repository factory refactor
Manual slug uniqueness validation

Breaks other manual validations
Fixed validations
Manual section slug uniqueness check
Add a <h2> for footnotes in manual documents

This allows manuals-frontend to correctly render an extra 'collapsible
section' for footnotes.
Merge pull request #217 from alphagov/add-heading-to-footnotes-for-manual-documents

Add a <h2> for footnotes in manual documents
Merge pull request #218 from alphagov/manual-slug-uniqueness

Manual slug uniqueness
Add missing require for development mode
Make sure version number is present

When we interact with PublicationLog we should make sure we alwayds have a version number amnd, for that matter, a slug as this will cause issues in the future.

This was being caught by Sidekiq when queueing publishing. It will also require migrations to be run in order to remove exisiting PublicationLogs again as there is some existing data we are aware of which currently breaks preview.
Merge pull request #220 from alphagov/bug/missing-attribute-on-publication-log

Make sure version number is present on PublicationLog