CBQE-1200: Implement multiple connection test to reproduce timeouts

Change-Id: Iee246c0d2fd32a1c4a1eb6f3c037c48d88739169
Reviewed-on: http://review.couchbase.org/25615
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>