Merge pull request plotly#854 from SamLau95/master

Update graphwidget to be compatible with new versions of iPython

Author: jackparmer

plotly/package_data/graphWidget.js

@@ -9,8 +9,8 @@
 from requests.compat import json as _json
 
 # TODO: protected imports?
-from IPython.html import widgets
-from IPython.utils.traitlets import Unicode
+import ipywidgets as widgets
+from traitlets import Unicode
 from IPython.display import Javascript, display
 
 import plotly.plotly.plotly as py
@@ -33,6 +33,7 @@ class GraphWidget(widgets.DOMWidget):
     Notebooks.
     """
     _view_name = Unicode('GraphView', sync=True)
+    _view_module = Unicode('graphWidget', sync=True)
     _message = Unicode(sync=True)
     _graph_url = Unicode(sync=True)
     _new_url = Unicode(sync=True)