Remove old 'google_insight' route

We definitely don't use this anymore; the controller no longer exists.
Remove old contact factory
Include FactoryGirl::Syntax::Methods in Cucumber
Allow new tags to be created

This adds a new tags controller to create new section or specialist 
sector tags.
Allow tags to be edited

This adds an edit form for editing the title and description for a tag.
List tags grouped by their parent

Add a method to the TagsController to group tags by the root/parent tags
after they are retrieved from the database. This also includes an
integration test for the tags list, and some CSS styling for the table.
Pre-fill tag type and parent information when present
Improve interface for managing tags

- Use list elements rather than tables to display the list of tags, so
  that we have clearer grouping of parents and their children.

- Add wells around form sections to keep similar appearance to
  artefact form.

- Add warning message above save buttons.

- Use a select field instead of disabled text box for tag type when
  creating a child tag.
Add curated list functionality for section tags

This takes the existing curated list functionality from the 'browse
section' controller, adding it to the new tags UI. I've added new
functional test coverage around this.

I've iterated this a bit, so that it doesn't increase the complexity
of the TagsController too much, and so it's styled to fit in with the
new tag form. However, it does come with a massive TODO noting that we
should improve how curated lists work soon.
Add error and success messages to the view

Include error messages in the tag create and edit forms, and add a
success notice into the application layout.

This makes the success notice code in the artefact template redundant,
so I've removed it.

Also includes an integration test for editing a tag.
Add test for displaying the curated list in the edit form
Require 'manage tags' permission to access tag UI

This adds a filter to the TagsController to assert the user has a
'manage_tags' permission.

This also updates the associated functional and integration tests so
that the stub users they test with are also given the permission.
Remove the BrowseSectionsController

The functionality it provided is now catered for in the TagsController.
Tidy up page titles
Bump govuk_content_models to 10.0.0

This includes the new validations on the Tag model.
Don't allow tag_id or parent_id params to be updated

The tag_id and parent_id parameters should not be changed for a tag 
once it has been created.

This changes the TagsController so that these two parameters are 
scrubbed when we update a tag which already exists.
Only prompt for the child portion of the slug

When creating a child tag, only ask the user to enter the child portion 
of the slug, and build the full tag ID in the controller's create action.

This adds a new Formtastic input type to handle this in an elegant way 
so that we still get error handling.
Merge pull request #149 from alphagov/better-tag-ui

Add new interface for managing section and specialist sector tags

https://www.pivotaltracker.com/story/show/66501256