Remove mapreduce recommendation from readme
Remove mapreduce recommendation from readme

Follow on to #2495

Chibin/gpdb,Quikling/gpdb,Quikling/gpdb,jmcatamney/gpdb,Quikling/gpdb,janebeckman/gpdb,ashwinstar/gpdb,cjcjameson/gpdb,jmcatamney/gpdb,edespino/gpdb,rvs/gpdb,Quikling/gpdb,greenplum-db/gpdb,kaknikhil/gpdb,adam8157/gpdb,cjcjameson/gpdb,edespino/gpdb,ashwinstar/gpdb,kaknikhil/gpdb,rvs/gpdb,50wu/gpdb,edespino/gpdb,xinzweb/gpdb,cjcjameson/gpdb,rvs/gpdb,50wu/gpdb,jmcatamney/gpdb,50wu/gpdb,xinzweb/gpdb,Chibin/gpdb,adam8157/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,yuanzhao/gpdb,Quikling/gpdb,edespino/gpdb,ashwinstar/gpdb,Chibin/gpdb,janebeckman/gpdb,50wu/gpdb,Quikling/gpdb,yuanzhao/gpdb,adam8157/gpdb,edespino/gpdb,lisakowen/gpdb,Quikling/gpdb,yuanzhao/gpdb,janebeckman/gpdb,ashwinstar/gpdb,xinzweb/gpdb,rvs/gpdb,janebeckman/gpdb,xinzweb/gpdb,Chibin/gpdb,yuanzhao/gpdb,xinzweb/gpdb,greenplum-db/gpdb,adam8157/gpdb,lisakowen/gpdb,edespino/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,janebeckman/gpdb,Chibin/gpdb,adam8157/gpdb,janebeckman/gpdb,xinzweb/gpdb,lisakowen/gpdb,rvs/gpdb,50wu/gpdb,50wu/gpdb,rvs/gpdb,jmcatamney/gpdb,janebeckman/gpdb,lisakowen/gpdb,Chibin/gpdb,janebeckman/gpdb,Chibin/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,Quikling/gpdb,yuanzhao/gpdb,jmcatamney/gpdb,rvs/gpdb,kaknikhil/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,Quikling/gpdb,lisakowen/gpdb,greenplum-db/gpdb,adam8157/gpdb,janebeckman/gpdb,rvs/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,janebeckman/gpdb,lisakowen/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,edespino/gpdb,greenplum-db/gpdb,Quikling/gpdb,greenplum-db/gpdb,Chibin/gpdb,edespino/gpdb,Chibin/gpdb,greenplum-db/gpdb,xinzweb/gpdb,50wu/gpdb,xinzweb/gpdb,greenplum-db/gpdb,edespino/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,lisakowen/gpdb,50wu/gpdb,yuanzhao/gpdb,adam8157/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,lisakowen/gpdb,adam8157/gpdb,ashwinstar/gpdb,rvs/gpdb,Chibin/gpdb,kaknikhil/gpdb,edespino/gpdb,cjcjameson/gpdb,rvs/gpdb,jmcatamney/gpdb,ashwinstar/gpdb