Remove unused gpenv.sh script

This isn't used by any utilities.
Authored-by: NChris Hajas <chajas@pivotal.io>

gpMgmt/bin/lib/gpenv.sh

-#!/usr/bin/env bash
-#
-# This is a bash script (since /bin/bash is guaranteed) that sets up the environment
-# needed to execute a python script.  It uses the path to itself as the basis from
-# which it determines GPHOME.
-
-# Get the absolute path to this script
-absPath=`cd $(dirname $0); pwd`
-
-# absPath is $GPHOME/bin/lib, so backup two directories to find $GPHOME
-GPHOME=$(dirname $(dirname $absPath))
-export GPHOME
-
-# get the PATH setup
-PATH=$GPHOME/bin:$GPHOME/ext/python/bin:$PATH
-export PATH
-
-# Set PYTHONPATH and HOME
-PYTHONPATH=$GPHOME/lib/python
-export PYTHONPATH
-PYTHONHOME=$GPHOME/ext/python
-export PYTHONHOME
-
-# Add in library paths appropriate for this system
-case `uname` in
-  Darwin) 
-     if [ $DYLD_LIBRARY_PATH ]
-     then DYLD_LIBRARY_PATH=$GPHOME/lib:$GPHOME/ext/python/lib:$DYLD_LIBRARY_PATH
-     else DYLD_LIBRARY_PATH=$GPHOME/lib:$GPHOME/ext/python/lib
-     fi
-     export DYLD_LIBRARY_PATH
-     ;;
-  *) 
-     if [ $LD_LIBRARY_PATH ]
-     then LD_LIBRARY_PATH=$GPHOME/lib:$GPHOME/ext/python/lib:$LD_LIBRARY_PATH
-     else LD_LIBRARY_PATH=$GPHOME/lib:$GPHOME/ext/python/lib
-     fi
-     export LD_LIBRARY_PATH
-     ;;
-esac
-
-
-# execute whatever was given to us
-if [ "$#" -gt 0 ]
-then eval $*
-else env
-fi