Update "validity of jpeg and png" test

IPython/core/tests/test_display.py

@@ -77,8 +77,8 b' def test_base64image():'
 def test_image_filename_defaults():
     '''test format constraint, and validity of jpeg and png'''
     tpath = ipath.get_ipython_package_dir()
-    # nt.assert_raises(ValueError, display.Image, filename=os.path.join(tpath, 'testing/tests/badformat.gif'),
-    #                  embed=True)
+    nt.assert_raises(ValueError, display.Image, filename=os.path.join(tpath, 'testing/tests/badformat.zip'),
+                     embed=True)
     nt.assert_raises(ValueError, display.Image)
     nt.assert_raises(ValueError, display.Image, data='this is not an image', format='badformat', embed=True)
     # check boths paths to allow packages to test at build and install time