Implement additional Event types

[matthewtckr]

Issue #24

[matthewtckr]

The additional Event types were found in analyzing my organization's Ticket Audits, and we currently have a Zendesk Support case open to get these items publicly documented.

[matthewtckr]

@reviewbybees

There's little doc on how to get this merged, let me know if there's a more-appropriate method than this.

Thanks,

[stephenc]

I just prefer to see the api documented before merging to master and releasing, but if you can share a public ticket where these event types are discussed that may suffice (depends on what's on the other end of the link)

[kzantow]

@matthewtckr agree with @stephenc - perhaps, at least add a brief class-level comment what the types are used for, if possible?

[matthewtckr]

Will do. Waiting on the final publish from Zendesk, and I will update the pull request. Thank you

[matthewtckr]

Updated the classes with Javadoc, including links to the Zendesk documentation that is now available for all three event types included.