Disable engine tests for win32 until they're fixed

Change-Id: Iaaec8442043e74eb8d24e4e84389aea349200281
Reviewed-on: http://review.couchbase.org/33987
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>