Add support for redirect rules

[Jonathan-Zollinger]

support zendesk redirect rules

• Search Redirect Rules
• Show Redirect Rule
• Set a redirect rule
• Delete Redirect Rule

This is complete when docs are supplemented with example usage (both successful calls and failures), and tests validate Zendesk's documented behavior - successful calls and failures (i.e. the updateUserSegment endpoint returns a 200 error code and the userSegmentObject created, thus tests should validate this and nothing more).