Kava Testnet 6000 Release Candidate 1

This release introduces the incentive and committee modules. Incentive rewards users who mint USDX with KAVA. Committee allows a subset of accounts to manage certain parameters of the system while still being accountable to regular token-holder governance. The official v8 release will serve as the basis for testnet-6000. Note that this code is still under audit and may undergo breaking changes before a release is finalized.