LU-3534 tests: a few tests cases for async update.

LU-3534 tests: a few tests cases for async update.

1 Add update migrate test case in conf-sanity.sh 32c.
2. add replay-dual.sh 26 to failover during tar and dbench.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I1431bfe8d076a16802d9bba7ca3a7b9d47745f5c
Reviewed-on: http://review.whamcloud.com/15163
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>