CBQE-1445: add tests for changing port and password

Change-Id: I13c4cbc2f911ff5ffea32a6d451911401815d2da
Reviewed-on: http://review.couchbase.org/27915
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>