Py keras extension (#3468)

* Added support for building Theano with GPU support.  Added a package
for the libgpuarry libary needed for Theano.

* Added dependency on py-pexpect package which ipython requires.

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

@@ -0,0 +1,42 @@
+##############################################################################
+# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/llnl/spack
+# Please also see the LICENSE file for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
+from spack import *
+
+
+class Libgpuarray(CMakePackage):
+    """Make a common GPU ndarray(n dimensions array) that can be reused by all
+    projects that is as future proof as possible, while keeping it easy to use
+    for simple need/quick test."""
+
+    homepage = "http://deeplearning.net/software/libgpuarray/"
+    url      = "https://github.com/Theano/libgpuarray/archive/v0.6.1.tar.gz"
+
+    version('0.6.2', '7f163bd5f48f399cd6e608ee3d528ee4')
+    version('0.6.1', 'cfcd1b54447f9d55b05514df62c70ae2')
+    version('0.6.0', '98a4ec1b4c8f225f0b89c18b899a000b')
+
+    depends_on('cuda')
+
+    extends('python')