Switch API repository to use nested exception
Switch API repository to use nested exception

We can switch this to use exception causes once we can upgrade
to Ruby 2.1.

See http://devblog.avdi.org/2013/12/25/exception-causes-in-ruby-2-1/

moneyadviceservice/frontend,moneyadviceservice/frontend,moneyadviceservice/frontend,moneyadviceservice/frontend