Allow memcached.endpoint to accept a list

[manishapme]

For services using AWS elasticache.memcache there's no value to using multiple nodes because you can only pass in one node as the endpoint.

If we allowed users to pass in a list of memcached nodes than the client library could handle the traffic routing automatically through it's hashing algorithm. https://pymemcache.readthedocs.io/en/latest/getting_started.html#using-a-memcached-cluster

[spladug]

Sounds good! Are you interested in taking this on?

[manishapme]

yes. but not immediately.