Add README file.
Add README file.

lpetrov-pivotal/gpdb,xuegang/gpdb,xuegang/gpdb,rvs/gpdb,zaksoup/gpdb,oberstet/postgres-xl,ovr/postgres-xl,snaga/postgres-xl,50wu/gpdb,Chibin/gpdb,tangp3/gpdb,greenplum-db/gpdb,randomtask1155/gpdb,Chibin/gpdb,jmcatamney/gpdb,Chibin/gpdb,janebeckman/gpdb,CraigHarris/gpdb,xinzweb/gpdb,adam8157/gpdb,tangp3/gpdb,kaknikhil/gpdb,xinzweb/gpdb,50wu/gpdb,edespino/gpdb,techdragon/Postgres-XL,Chibin/gpdb,foyzur/gpdb,0x0FFF/gpdb,jmcatamney/gpdb,royc1/gpdb,Quikling/gpdb,Postgres-XL/Postgres-XL,snaga/postgres-xl,edespino/gpdb,yuanzhao/gpdb,rubikloud/gpdb,postmind-net/postgres-xl,lpetrov-pivotal/gpdb,xinzweb/gpdb,Chibin/gpdb,xuegang/gpdb,kaknikhil/gpdb,royc1/gpdb,zaksoup/gpdb,lisakowen/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,oberstet/postgres-xl,adam8157/gpdb,arcivanov/postgres-xl,rvs/gpdb,edespino/gpdb,rvs/gpdb,50wu/gpdb,janebeckman/gpdb,atris/gpdb,janebeckman/gpdb,50wu/gpdb,yazun/postgres-xl,yuanzhao/gpdb,postmind-net/postgres-xl,randomtask1155/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,lintzc/gpdb,xinzweb/gpdb,snaga/postgres-xl,greenplum-db/gpdb,kmjungersen/PostgresXL,xinzweb/gpdb,janebeckman/gpdb,0x0FFF/gpdb,janebeckman/gpdb,zaksoup/gpdb,Quikling/gpdb,kaknikhil/gpdb,techdragon/Postgres-XL,atris/gpdb,chrishajas/gpdb,CraigHarris/gpdb,lisakowen/gpdb,CraigHarris/gpdb,chrishajas/gpdb,zeroae/postgres-xl,jmcatamney/gpdb,kaknikhil/gpdb,techdragon/Postgres-XL,ahachete/gpdb,foyzur/gpdb,lisakowen/gpdb,rvs/gpdb,adam8157/gpdb,lintzc/gpdb,adam8157/gpdb,cjcjameson/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,50wu/gpdb,jmcatamney/gpdb,rubikloud/gpdb,zeroae/postgres-xl,Chibin/gpdb,royc1/gpdb,Quikling/gpdb,foyzur/gpdb,arcivanov/postgres-xl,edespino/gpdb,ahachete/gpdb,royc1/gpdb,Chibin/gpdb,rvs/gpdb,edespino/gpdb,arcivanov/postgres-xl,atris/gpdb,zaksoup/gpdb,arcivanov/postgres-xl,kaknikhil/gpdb,janebeckman/gpdb,adam8157/gpdb,zaksoup/gpdb,Quikling/gpdb,kaknikhil/gpdb,greenplum-db/gpdb,randomtask1155/gpdb,cjcjameson/gpdb,yazun/postgres-xl,pavanvd/postgres-xl,randomtask1155/gpdb,randomtask1155/gpdb,rvs/gpdb,chrishajas/gpdb,lintzc/gpdb,tangp3/gpdb,lisakowen/gpdb,tpostgres-projects/tPostgres,edespino/gpdb,arcivanov/postgres-xl,yuanzhao/gpdb,Chibin/gpdb,ovr/postgres-xl,royc1/gpdb,ahachete/gpdb,Postgres-XL/Postgres-XL,CraigHarris/gpdb,rvs/gpdb,royc1/gpdb,foyzur/gpdb,atris/gpdb,Quikling/gpdb,CraigHarris/gpdb,cjcjameson/gpdb,tangp3/gpdb,oberstet/postgres-xl,pavanvd/postgres-xl,lpetrov-pivotal/gpdb,chrishajas/gpdb,xuegang/gpdb,chrishajas/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,CraigHarris/gpdb,jmcatamney/gpdb,atris/gpdb,zeroae/postgres-xl,foyzur/gpdb,royc1/gpdb,techdragon/Postgres-XL,50wu/gpdb,0x0FFF/gpdb,0x0FFF/gpdb,rubikloud/gpdb,pavanvd/postgres-xl,xuegang/gpdb,chrishajas/gpdb,lpetrov-pivotal/gpdb,jmcatamney/gpdb,0x0FFF/gpdb,xuegang/gpdb,oberstet/postgres-xl,cjcjameson/gpdb,ahachete/gpdb,xinzweb/gpdb,kmjungersen/PostgresXL,rubikloud/gpdb,kaknikhil/gpdb,randomtask1155/gpdb,xuegang/gpdb,ashwinstar/gpdb,tangp3/gpdb,rvs/gpdb,rubikloud/gpdb,postmind-net/postgres-xl,yuanzhao/gpdb,Chibin/gpdb,ashwinstar/gpdb,lisakowen/gpdb,ahachete/gpdb,CraigHarris/gpdb,adam8157/gpdb,pavanvd/postgres-xl,0x0FFF/gpdb,Chibin/gpdb,lintzc/gpdb,Postgres-XL/Postgres-XL,rubikloud/gpdb,lintzc/gpdb,tpostgres-projects/tPostgres,lpetrov-pivotal/gpdb,ovr/postgres-xl,cjcjameson/gpdb,yuanzhao/gpdb,lintzc/gpdb,lintzc/gpdb,greenplum-db/gpdb,lisakowen/gpdb,zeroae/postgres-xl,rubikloud/gpdb,tpostgres-projects/tPostgres,oberstet/postgres-xl,Postgres-XL/Postgres-XL,0x0FFF/gpdb,ashwinstar/gpdb,xinzweb/gpdb,greenplum-db/gpdb,lpetrov-pivotal/gpdb,adam8157/gpdb,lintzc/gpdb,atris/gpdb,postmind-net/postgres-xl,Quikling/gpdb,kaknikhil/gpdb,kmjungersen/PostgresXL,ovr/postgres-xl,ashwinstar/gpdb,CraigHarris/gpdb,tangp3/gpdb,cjcjameson/gpdb,lisakowen/gpdb,ahachete/gpdb,xuegang/gpdb,zaksoup/gpdb,ahachete/gpdb,kmjungersen/PostgresXL,yazun/postgres-xl,royc1/gpdb,greenplum-db/gpdb,atris/gpdb,Quikling/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,adam8157/gpdb,lpetrov-pivotal/gpdb,Quikling/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,edespino/gpdb,zaksoup/gpdb,atris/gpdb,0x0FFF/gpdb,50wu/gpdb,lintzc/gpdb,lisakowen/gpdb,tpostgres-projects/tPostgres,cjcjameson/gpdb,rvs/gpdb,tpostgres-projects/tPostgres,Quikling/gpdb,janebeckman/gpdb,kaknikhil/gpdb,xinzweb/gpdb,chrishajas/gpdb,Quikling/gpdb,kmjungersen/PostgresXL,arcivanov/postgres-xl,yuanzhao/gpdb,xuegang/gpdb,cjcjameson/gpdb,edespino/gpdb,techdragon/Postgres-XL,postmind-net/postgres-xl,randomtask1155/gpdb,zaksoup/gpdb,Postgres-XL/Postgres-XL,chrishajas/gpdb,snaga/postgres-xl,ashwinstar/gpdb,kaknikhil/gpdb,rubikloud/gpdb,zeroae/postgres-xl,rvs/gpdb,edespino/gpdb,foyzur/gpdb,50wu/gpdb,yazun/postgres-xl,CraigHarris/gpdb,janebeckman/gpdb,ovr/postgres-xl,snaga/postgres-xl,edespino/gpdb,tangp3/gpdb,tangp3/gpdb,lpetrov-pivotal/gpdb,pavanvd/postgres-xl,ahachete/gpdb,randomtask1155/gpdb,janebeckman/gpdb,janebeckman/gpdb,yazun/postgres-xl,foyzur/gpdb,foyzur/gpdb,yuanzhao/gpdb