MB-100: run tearDown in setup if it failed in prev test

Change-Id: I1fa6a565d2337d64fbd13fee6c15a1512edbf9ab
Reviewed-on: http://review.couchbase.org/24300
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
MB-7074: add small scale xperf test for win

Change-Id: Iceabf85522430d639d22a80adfd041b032aef004
Reviewed-on: http://review.couchbase.org/24306
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>
Tested-by: Pavel Paulau <pavel.paulau@gmail.com>