Fail on bad use of traitlets.

Carreau · Carreau · commit 03e6b0c099d2 · 2016-06-07T13:29:37.000-07:00
diff --git a/IPython/testing/iptest.py b/IPython/testing/iptest.py
@@ -47,6 +47,7 @@
 warnings.filterwarnings('ignore', message='.*Matplotlib is building the font cache.*', category=UserWarning, module='.*')
 if sys.version_info > (3,0):
     warnings.filterwarnings('error', message='.*', category=ResourceWarning, module='.*')
+warnings.filterwarnings('error', message=".*{'config': True}.*", category=DeprecationWarning, module='IPy.*')
 warnings.filterwarnings('default', message='.*', category=Warning, module='IPy.*')
 
 if version_info < (6,):
