CBQE-2145: added warm up progress check test

Change-Id: Id2b2b2b71f35a8c70cb2dadb7514cea04e69e071
Reviewed-on: http://review.couchbase.org/34851
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: buildbot <build@couchbase.com>