* reran the simple form initializer.
* wrapped submit buttons are now broken and need a fix.
* disabled confirmation validation in client side validations as the
  error message always is attached to the wrong field.

our special error handler for json requests would turn all exceptions
into 500s - removed it. now the rescue_responses can do their thing
again.

update all the dependencies.

minitest now wants assert_nil instead of assert_equal nil, ...
braintree now uses update_attributes rather than save.

Used to fail because the record already existed in the database
fixes #17

enable testing error responses on the full rack stack.

That's the only thing the controller handles meaningful.
Before the route would also catch anything that started with a . interpreting
it as a format string. This lead to lots of false positives in our security
scanner.

Related with https://github.com/pixelated/pixelated-user-agent/issues/924
With @aarni