Removes custom `#set_flash_message` method used to show devise messages as "success" rather than the default "notice".
Merge pull request #775 from moneyadviceservice/devise_flash_messages

Shows devise messages as "notice" rather than "success".
Fixing issue which has crept to LIVE environment which resulted in the
clear input script not firing it's events

There was a change a few weeks ago to the DoughBaseComponents.js, in which
uiEvents were now taken from the config which is passed in when the component
is created. Clear input was not updated to follow this new convention