feat(annotations): initial implementation for annotations
fix(test): Ignore all queries with pg_ when counting queries
Move require encrypted_column statement to individual models
Merge branch 'master' into hh-add-links-to-jobs
Tweak AnnotationProvider.authenticate_provider
Remove image_url and image_alt from Annotations

Images that 3rd parties can add without our approval can appear
incongruous on our pages.
Add 'status' attribute to Annotations as String
Update annotations via service

Eschew callbacks
Eradicate ActiveRecord callbacks from Annotation
Privatize Annotation validator
Rework FindJob#updated_at
Cache annotation object in UpdateAnnotation#run

Caching saves 2 DB queries.
The number in `#issue_queries` may fluctuate, but it should be
set to the bare minimum required to perform a single
`#annotation` call and a single `#update_attributes!` call.
Revert "Rework FindJob#updated_at"

This reverts commit 683b224f863cc946c10f4ff8e4f551ceb24e1da0.

This caused travis-api specs to fail in a rather puzzling way.
https://travis-ci.org/travis-ci/travis-api/builds/17412741
Eschew use of #flatten

Arguably this is personal taste, but I believe this reads better.
Reinstate #max
Merge branch 'master' into hh-add-links-to-jobs
Merge pull request #233 from travis-ci/hh-add-links-to-jobs

Implement annotations (#1220)