Naive fix for deprecation warning.

`DeprecationWarning: Importing from numpy.testing.decorators is deprecated, import from numpy.testing instead.`

IPython/external/decorators/__init__.py

@@ -1,5 +1,5 b''
 try:
-    from numpy.testing.decorators import *
+    from numpy.testing import *
     from numpy.testing.noseclasses import KnownFailure
 except ImportError:
     from ._decorators import *