remove unused yaml and bash script (#3905)

Signed-off-by: NGoutam Tadi <gtadi@pivotal.io>

concourse/scripts/compile_gpdb_and_orca_with_conan_ubuntu.bash

-#!/bin/bash
-
-set -u -e -x
-
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
-
-GPDB_INSTALL_DIR=/tmp/gpdb_install_dir
-mkdir -p ${GPDB_INSTALL_DIR}
-
-# outputs compiled bits to CWD/bin_orca
-${DIR}/build_orca.py --bintrayRemote=${BINTRAY_REMOTE} --bintrayRemoteURL=${BINTRAY_REMOTE_URL} --env_additions="CC=/usr/bin/gcc-5 CXX=/usr/bin/g++-5"
-
-${DIR}/build_gpdb.py --mode=orca --output_dir=${GPDB_INSTALL_DIR} bin_orca
-
-tar czf ${GPDB_DST_TARBALL} -C ${GPDB_INSTALL_DIR} .
-tar czf ${ORCA_DST_TARBALL} bin_orca/usr/local/include bin_orca/usr/local/lib -C bin_orca/usr/local .

concourse/tasks/compile_gpdb_and_orca_with_conan.yml

-platform: linux
-image_resource:
-  type: docker-image
-  source:
-    repository: pivotaldata/ubuntu-gpdb-dev
-    tag: '16.04_gcc_6_3'
-inputs:
-  - name: gpdb_src
-outputs:
-  - name: compiled_bits_gpdb_with_orca_conan_ubuntu16
-  - name: compiled_bits_orca_with_conan_ubuntu16
-run:
-  path: gpdb_src/concourse/scripts/compile_gpdb_and_orca_with_conan_ubuntu.bash
-params:
-  BINARY_USER: required
-  BINARY_REMOTE_URL: required
-  GPDB_DST_TARBALL: compiled_bits_gpdb_with_orca_conan_ubuntu16/compiled_bits_gpdb_orca_ubuntu16.tar.gz
-  ORCA_DST_TARBALL: compiled_bits_orca_with_conan_ubuntu16/compiled_bits_orca_with_conan_ubuntu16.tar.gz