CBQE-0 : Run tearDown when setup fails

Change-Id: Ice99772ad6d809f04dc2977ffc24632bafa83bfb
Reviewed-on: http://review.couchbase.org/38961
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Reviewed-by: Meenakshi Goel <meenakshi.goel@globallogic.com>