Bump Impala version to 2.6.0
Bump Impala version to 2.6.0

Change-Id: Ia1b8b6de080f7bdc59a5e350dadd36502aaecc4e
Reviewed-on: http://gerrit.cloudera.org:8080/2409
Reviewed-by: Harrison Sheinblatt <cc16de7cfd71b6e691bd92d53ef9935bf8dc2f22@hotmail.com>
Tested-by: Juan Yu <34a62e20de6070542c7bca4f0f49d6e4786ad51e@cloudera.com>

ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC