Neo4j (#16068)

* Update var/spack/repos/builtin/packages/neo4j/package.py

Co-Authored-By: Adam J. Stewart <ajstewart426@gmail.com>

* Add new package: neo4j

* refine neo4j package

* fix flake8 warning

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

var/spack/repos/builtin/packages/neo4j/package.py

@@ -0,0 +1,31 @@
+# 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 Neo4j(Package):
+    """Neo4j is the world's leading Graph Database. It is a high performance
+    graph store with all the features expected of a mature and robust
+    database, like a friendly query language and ACID transactions. The
+    programmer works with a flexible network structure of nodes and
+    relationships rather than static tables--yet enjoys all the benefits of
+    enterprise-quality database. For many applications, Neo4j offers orders
+    of magnitude performance benefits compared to relational DBs."""
+
+    homepage = "http://neo4j.com/"
+    url      = "https://github.com/neo4j/neo4j/archive/4.0.3.tar.gz"
+
+    version('4.0.3',  sha256='19d79052657665dd661bbe906b3552b88108bf379d39fa007b883fff718cabee')
+    version('4.0.1',  sha256='3f91f566e49000119c6a71d6127e73cfccdee37b68133a067b2ee05932c26dba')
+    version('4.0.0',  sha256='7173b97baf53be82b46f95fa52f99af591606a318e03915917ddd7141936fec5')
+    version('3.5.16', sha256='1304fcd56b0f08f35b05d8b546fd844637ba1ffa5e00bb1e9a81a06b6242cb88')
+
+    depends_on('maven', type=('build', 'run'))
+
+    def install(self, spec, prefix):
+        maven = which('mvn')
+        maven('clean', 'install', '-DskipTests')
+        install_tree('.', prefix)