Added * Added `is_updated` to publishable resources. [contentful-management.rb/178](https://github.com/contentful/contentful-management.rb/issues/178)
2.6.1
Fixed * Fixed an issue with `deepcopy` not being able to properly clone resources. * Fixed an issue with properties missing from an entry that were not being able to be resolved to a field.
2.6.0
Added * Added Usage Periods API * Added API Usages API