Commented Feature: Implement Get Muted Users [2216]

Get a list of user objects that have been muted: [https://dev.twitter.com/docs/api/1.1/get/mutes/users/list](https://dev.twitter.com/docs/api/1.1/get/mutes/users/list)
Comments: Associated with changeset 42701: Version 0.9.7.0
- Implemented GetMuted Users