ACCUMULO-2227 / ACCUMULO-2228 Update randomwalk README with HA warning
ACCUMULO-2227 / ACCUMULO-2228 Update randomwalk README with HA warning

Hadoop 2.1.0 includes better retry / failover handling than prior versions. This
commit adds a warning to the randomwalk README advising testers to expect more
failures exercising HA under Hadoop versions before 2.1.0.

apache/accumulo,dhutchis/accumulo,adamjshook/accumulo,ivakegg/accumulo,phrocker/accumulo-1,joshelser/accumulo,mikewalch/accumulo,ctubbsii/accumulo,lstav/accumulo,mjwall/accumulo,phrocker/accumulo,phrocker/accumulo,apache/accumulo,keith-turner/accumulo,mikewalch/accumulo,keith-turner/accumulo,adamjshook/accumulo,ctubbsii/accumulo,apache/accumulo,phrocker/accumulo,dhutchis/accumulo,mikewalch/accumulo,ivakegg/accumulo,keith-turner/accumulo,joshelser/accumulo,lstav/accumulo,milleruntime/accumulo,mikewalch/accumulo,ivakegg/accumulo,ivakegg/accumulo,dhutchis/accumulo,mjwall/accumulo,phrocker/accumulo-1,lstav/accumulo,milleruntime/accumulo,mjwall/accumulo,mikewalch/accumulo,apache/accumulo,milleruntime/accumulo,phrocker/accumulo-1,apache/accumulo,lstav/accumulo,keith-turner/accumulo,adamjshook/accumulo,phrocker/accumulo,ivakegg/accumulo,joshelser/accumulo,phrocker/accumulo-1,mjwall/accumulo,dhutchis/accumulo,adamjshook/accumulo,milleruntime/accumulo,ctubbsii/accumulo,phrocker/accumulo,phrocker/accumulo,phrocker/accumulo,dhutchis/accumulo,ctubbsii/accumulo,milleruntime/accumulo,keith-turner/accumulo,joshelser/accumulo,adamjshook/accumulo,ctubbsii/accumulo,adamjshook/accumulo,joshelser/accumulo,adamjshook/accumulo,adamjshook/accumulo,mjwall/accumulo,apache/accumulo,lstav/accumulo,phrocker/accumulo-1,adamjshook/accumulo,mikewalch/accumulo,apache/accumulo,joshelser/accumulo,phrocker/accumulo-1,dhutchis/accumulo,milleruntime/accumulo,dhutchis/accumulo,lstav/accumulo,ctubbsii/accumulo,phrocker/accumulo,milleruntime/accumulo,ctubbsii/accumulo,ivakegg/accumulo,dhutchis/accumulo,keith-turner/accumulo,mikewalch/accumulo,ivakegg/accumulo,lstav/accumulo,mikewalch/accumulo,dhutchis/accumulo,joshelser/accumulo,joshelser/accumulo,phrocker/accumulo-1,mjwall/accumulo,phrocker/accumulo,keith-turner/accumulo,mjwall/accumulo