[VOTE] CEP-50: Authentication Negotiation

[Joel Shepherd]

Hi dev@ - I'd like to request voting for adoption of CEP-50: 
Authentication Negotiation.

Proposal: 
https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-50%3A+Authentication+Negotiation
Discussion: https://lists.apache.org/thread/cdx4fttq72j4dz7cyhxp14pt7k6rd6bc
Feedback has been incorporated in the proposal, or (I believe) closed 
out in the discussion thread.

The vote will be open for 72 hours. A vote passes if there are at least 
3 binding +1s and no binding vetoes.

Thanks! -- Joel.