Fixed Theano GPU support (#7325)

* Added a package for the MDAnalysis toolkit.

* Added a new package for pygpu, which is the python front end of the
libgpuarray.  Additionally changed the dependency for theano so that
it properly picks up the pygpu library.

* Added the libcheck package.  Fixed flake8 errors in py-pygpu recipe
and removed spurious dependency on cudnn for libgpuarray.

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

@@ -33,11 +33,17 @@ class Libgpuarray(CMakePackage):
     homepage = "http://deeplearning.net/software/libgpuarray/"
     url      = "https://github.com/Theano/libgpuarray/archive/v0.6.1.tar.gz"
 
+    version('0.7.5', '2534011464555c3e99d14231db965c20')
+    version('0.7.4', '19f57cd381175162048c8154f5251546')
+    version('0.7.3', 'cb44aeb8482330974abdb36b0a477e5d')
+    version('0.7.2', '0f9d7748501bc5c71bf04aae2285ac4e')
+    version('0.7.1', '7eb5bb6689ddbc386a9d498f5c0027fb')
+    version('0.7.0', 'f71b066f21ef7666f3a851e96c26f52e')
+    version('0.6.9', '7f75c39f1436c920ed9c5ffde5631fc0')
     version('0.6.2', '7f163bd5f48f399cd6e608ee3d528ee4')
     version('0.6.1', 'cfcd1b54447f9d55b05514df62c70ae2')
     version('0.6.0', '98a4ec1b4c8f225f0b89c18b899a000b')
 
     depends_on('cuda')
     depends_on('cmake@3:', type='build')
-
-    extends('python')
+    depends_on('libcheck')