Added Error definition for norm function.

theano/sandbox/linalg/ops.py

@@ -1256,7 +1256,7 @@ def norm(x,ord):
         else:
             raise ValueError(0)
     elif ndim > 2:
-        raise NotImplementedError
+        raise NotImplementedError("We don't support norm witn ndim > 2")
 
 class lstsq(theano.Op):
     def __eq__(self, other):

theano/sandbox/linalg/tests/test_linalg.py

@@ -40,6 +40,7 @@ from theano.sandbox.linalg import eig, eigh, eigvalsh
 from nose.plugins.skip import SkipTest
 from nose.plugins.attrib import attr
 
+
 def check_lower_triangular(pd, ch_f):
     ch = ch_f(pd)
     assert ch[0, pd.shape[1] - 1] == 0