HBASE-22405 Update Ref Guide for EOL of Hadoop 2.7
HBASE-22405 Update Ref Guide for EOL of Hadoop 2.7

Signed-off-by: Andrew Purtell <b91237ce35d325aea9eacb2c17af89139c6c9289@apache.org>

ChinmaySKulkarni/hbase,ultratendency/hbase,apurtell/hbase,francisliu/hbase,apurtell/hbase,ultratendency/hbase,ChinmaySKulkarni/hbase,ultratendency/hbase,Apache9/hbase,apurtell/hbase,Apache9/hbase,ndimiduk/hbase,ChinmaySKulkarni/hbase,mahak/hbase,ChinmaySKulkarni/hbase,francisliu/hbase,francisliu/hbase,ndimiduk/hbase,ndimiduk/hbase,ndimiduk/hbase,Apache9/hbase,mahak/hbase,ultratendency/hbase,ndimiduk/hbase,apurtell/hbase,Apache9/hbase,ultratendency/hbase,ultratendency/hbase,mahak/hbase,ChinmaySKulkarni/hbase,Apache9/hbase,ndimiduk/hbase,francisliu/hbase,mahak/hbase,mahak/hbase,francisliu/hbase,ndimiduk/hbase,mahak/hbase,apurtell/hbase,mahak/hbase,ChinmaySKulkarni/hbase,ChinmaySKulkarni/hbase,ultratendency/hbase,francisliu/hbase,francisliu/hbase,francisliu/hbase,mahak/hbase,Apache9/hbase,ndimiduk/hbase,ndimiduk/hbase,ultratendency/hbase,Apache9/hbase,Apache9/hbase,apurtell/hbase,apurtell/hbase,francisliu/hbase,apurtell/hbase,apurtell/hbase,francisliu/hbase,ultratendency/hbase,Apache9/hbase,Apache9/hbase,apurtell/hbase,ultratendency/hbase,ndimiduk/hbase,mahak/hbase,ChinmaySKulkarni/hbase,ChinmaySKulkarni/hbase,ChinmaySKulkarni/hbase,mahak/hbase