MB-10740 Don't spawn epmd in cluster_run.

As far as I can tell, erlang is capable of doing this on its own.

Change-Id: I733a0c5e549803c235f79e998a61bf89c6d9261e
Reviewed-on: http://review.couchbase.org/35473
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>