Another attempt at blacklisting collections for dreload

Making a PR to see what Travis thinks

IPython/lib/tests/test_deepreload.py

@@ -27,15 +27,10 b' def test_deepreload_numpy():'
         # Standard exclusions:
         'sys', 'os.path', builtin_mod_name, '__main__',
         # Test-related exclusions:
-        'unittest', 'UserDict', '_collections_abc', 'tokenize'
+        'unittest', 'UserDict', '_collections_abc', 'tokenize',
+        'collections', 'collections.abc'
         ]
 
-    # `collections` builtin shall not be reloaded to avoid failure
-    # of lib.pretty collections related pretty printing.
-    # of course this make nose crash on Py3 because of Py 2.3 compat...
-    if not PY3:
-        exclude.append('collections')
-
     dreload(numpy, exclude=exclude)
 
 def test_deepreload():