Add mortgage_calculator gem. Add an initializer for mortgage calculator.
Add engine ToolMountPoint and routing.
correctly handle the different urls for stamp duty and mortgage affordability tools.
Features to test mortgage calculator engine integration.
If requirejs isn't available, don't load requirejs.config.
wrap mortage calculator tools in a feature flag
Merge pull request #719 from moneyadviceservice/mount_mortgage_calculator

Mount mortgage_calculator
Add landing page to the styleguide
Move content out into YML files
Add fake home link to breadcrumbs
Rename landing_page to annuities
Merge pull request #720 from moneyadviceservice/landing_page

Template for the Annuities Landing Page
Debt Free Day Integration: add dependency to the Gemfile
Debt Free Day Integration: update schema.rb after running migrations
Debt Free Day Integration: make sure the engine inherits the correct controller / layout
Debt Free Day Integration: add a Cucumber feature to test integration
Debt Free Day Integration: save cassettes after running Cucumber feature

These cassettes cache the API calls made for categories when running the
Cucumber feature for the new engine.
Debt Free Day Integration: create a ToolMountPoint and mount the engine

This tool mount point needs to be able to expose routes for 2 separate
calculators. The changes required to achieve this were:

* override the `match?` request matcher method
* override `alternate_tool_id`
* make it clear `en_id` and `cy_id` are not supported as there is no
  single tool id for this tool mount point
Debt Free Day Integration: wrap in a feature block.
Debt Free Day Integration: add bower dependency on the engine

Also group the MAS imports together.