Remove python 2 only long and unicode type references.

IPython/lib/pretty.py

@@ -764,10 +764,6 b' except AttributeError: # Python 3'
         _dict_pprinter_factory('mappingproxy({', '})')
     _type_pprinters[slice] = _repr_pprint
 
-try:
-    _type_pprinters[long] = _repr_pprint
-    _type_pprinters[unicode] = _repr_pprint
-except NameError:
     _type_pprinters[range] = _repr_pprint
     _type_pprinters[bytes] = _repr_pprint