CBQE-1449: add test for restricted bucket names

Change-Id: Ic5adc360dec0c645746c396657cfdbd529302de4
Reviewed-on: http://review.couchbase.org/37312
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>