CBQE-0: put all keys tests to joins class

Change-Id: I21a47d9dacaa236f2688ae6ce4107bf55608fc12
Reviewed-on: http://review.couchbase.org/33169
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>