Remove gpugpart.pl and README

* gpugpart.pl is a utility to upgrade 3.1 -> 3.2
Signed-off-by: NMelanie Plageman <mplageman@pivotal.io>

gpMgmt/bin/README

@@ -29,7 +29,6 @@ Where Things Go
 
 List of Management Scripts Written in Perl
 ------------------------------------------
-bin/gpugpart.pl         -  Upgrades postgres style partition to Greenplum partitioning
 bin/run_operator_tests.pl -
 
 List of Management Scripts Written in Bash