Support for Segments endpoints

[davidski]

Thanks so much for this package!

Any chance support for the GET portions of the lists segments endpoints (https://mailchimp.com/developer/marketing/api/list-segments/ and https://mailchimp.com/developer/marketing/api/list-segment-members/) could be implemented? Segments are mailchimps way of breaking audiences (lists) into discrete groupings, allowing a single audience to be used for multiple target groups. I use this to ensure contact information is consistent across an account as well as cutting down on subscription costs for duplicate contacts.

Goal would be to list the available segments and get the members that comprise each segment within an audience.

Thanks again!