Made registered model name look like other model names

IPython/html/static/notebook/js/widgets/container.js

@@ -1,6 +1,6 b''
 require(["notebook/js/widget"], function(){
     var ContainerModel = IPython.WidgetModel.extend({});
-    IPython.notebook.widget_manager.register_widget_model('container_widget', ContainerModel);
+    IPython.notebook.widget_manager.register_widget_model('ContainerWidgetModel', ContainerModel);
 
     var ContainerView = IPython.WidgetView.extend({
         

IPython/html/widgets/widget_container.py

@@ -2,7 +2,7 b' from widget import Widget'
 from IPython.utils.traitlets import Unicode, Bool
 
 class ContainerWidget(Widget):
-    target_name = Unicode('container_widget')
+    target_name = Unicode('ContainerWidgetModel')
     default_view_name = Unicode('ContainerView')
     _keys = ['_vbox', '_hbox', '_start', '_end', '_center']
     _trait_changing = False