Bump content models
Add rest-client gem

This is temporary whilst working out the asset-manager
integration and will be removed
Add AssetUploader

This probably lives in api-adapters and will be
implemented there instead soon.
Add methods to upload assets to TravelAdviceEdition
Add feature spec for uploading an image
Load api_adapters from local environment
Remove asset_uploader
Upload images using GdsApi::AssetManager
Expose the asset ID in the edit form

This is to be replaced by the actual asset once
serving assets has been completed.
Bump gds-api-adapters to 5.0.0
Bump api adapters to 5.0.1
Initialise a single asset manager api client
Invoke the create_asset method with a hash, not a file
Display the currently uploaded image in the edit form
Allow assets to be uploaded for the document field

Rewritten the attachment methods with a bit of
metaprogramming to support other fields.

More comprehensive unit tests too.
Catch GdsApi errors raised during the upload

Make sure this doesn't break the callback chain
and stop anything else from being saved.
Remove rest-client

This was only added as an interim before there was an api-adapter
Add document and image uploads to edit form
Catch any upload errors and send them in a flash alert
Merge remote branch 'origin/master' into add-map-image-and-pdf

Conflicts:
	Gemfile
	Gemfile.lock
	app/views/admin/editions/edit.html.erb