Add toggled show hide message and aria role to js.
refactored collapsable.js to be a require module
moved to correct folder and modified loading to work correctly
added unit test for collapsable
minor refactor of spec files
updated accessibility toggle to change aria value rather then add / remove.
Merge pull request #53 from moneyadviceservice/article_page/accessibility_fixes

Change the collapsible element so that it is accessible. 
Refactor collapsable code to use requirejs