although the constructor is deprecated at least assign the attributes
not used and doesn't matter
use service crud module also for account, invoice & item
include error message in invalid model exceptions on create
Merge pull request #72 from cobot/master

more use of crud_service, more helpful errors
Merge pull request #73 from nickhammond/nokogiri-freeze

freeze nokogiri at 1.5.x as in 1.6 support for < Ruby 1.9 has been removed.