chargebacks: fix display of payment method in chargebacks form

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
version: bump to 0.2.4

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
Gemfile.lock: update Kaui to 0.2.4

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>