[Fix] Article ID is a long
[Fix] Article ID is a long

https://github.com/cloudbees/zendesk-java-client/blob/master/src/main/java/org/zendesk/client/v2/model/hc/Article.java#L11
https://developer.zendesk.com/rest_api/docs/help_center/articles#json-format (marked as int but they aren't  - it is the same for others objects)

matthewtckr/zendesk-java-client,cloudbees/zendesk-java-client,gvh1234/zendesk-java-client,christ66/zendesk-java-client,norrisjeremy/zendesk-java-client