Updated spec helper, so that when running tests, it's running against the validation service
Extracted sample feed into an examples module
Added all example feeds from the blog
Changed the themeparty category type to general
Updated title and uri/link postprocessing steps to not set the ID if already set
Pushing an invalid feed now raises an error
Added a validate method, which raises an exception with a propper error message
Added examples from the blog to regular test run
Added a validation of currency in dependence of value being present or not
Fixed attribute validation: mandatory and max_occurs now work correctly