Added support for Zendesk KB.
Support for Zendesk KB

- Removed the HSZenDeskKBItem class. Using the HSKBItem class instead.
- Added optional category property
- Removed the localArticlePath parameter in the init method of
HSZenDeskGear
Fixed missing issues from previous commit

- Deleted HSZenDeskKBItem
- Added sections support for Zendesk
Merge pull request #25 from happyfoxinc/pr/16

Support for Zendesk KB