Add disabled, disabled_at, edit_history_summary and errors fields to Invoice#126

wscourge merged 8 commits intomainchartmogul/chartmogul-python:mainfrom

wiktor/ome-418-add-validation_type-support-to-invoices-line-items-andchartmogul/chartmogul-python:wiktor/ome-418-add-validation_type-support-to-invoices-line-items-andCopy head branch name to clipboard