add new package : gpdb (#14440)

* add new package : gpdb

* update docstring and license info

var/spack/repos/builtin/packages/gpdb/package.py

+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Gpdb(AutotoolsPackage):
+    """
+    Greenplum Database (GPDB) is an advanced, fully featured, open source
+    data warehouse, based on PostgreSQL. It provides powerful and rapid
+    analytics on petabyte scale data volumes. Uniquely geared toward big
+    data analytics, Greenplum Database is powered by the world's most
+    advanced cost-based query optimizer delivering high analytical query
+    performance on large data volumes.
+    """
+
+    homepage = "https://github.com/greenplum-db/gpdb"
+    url      = "https://github.com/greenplum-db/gpdb/archive/6.2.1.tar.gz"
+
+    version('6.2.1',     sha256='60c81d71665d623ea98a0e9bd8e6df7fecf6b30eb60a5881ccef781ff5214438')
+    version('6.1.0',     sha256='81fa854b0ac5fe4e0de5fdee9a7b7c2514e1ea1feefa4e4d10518538a5c5b2a8')
+    version('6.0.1',     sha256='8902f5d64386447f61c25686f283a785858760e0dcf9a049266db058d3597156')
+    version('6.0.0',     sha256='8514140bee9db514d18a769034562e7f3464f74828595903a64dbf3d175ab71a')
+    version('5.24.0',    sha256='4ea5cfcc20f149669bb3713378158e15b5c5949b367351a0f497ba1602d61fc1')
+    version('5.23.0',    sha256='b06a797eb941362d5473b84d5def349b5ce12ce87ab116bea7c74ad193738ae9')
+
+    depends_on('zstd')
+    depends_on('apr')
+    depends_on('libevent')
+    depends_on('curl')
+    depends_on('xerces-c')
+    depends_on('bison', type='build')
+    depends_on('libxml2')
+    depends_on('flex')
+    depends_on('readline')
+
+    def configure_args(self):
+        args = ['--disable-orca']
+        return args