Fix use of Flash app to handle dash code change (#166)

* Fix use of Flash app to handle dash code change

* Remove spurious import

Author: delsim

django_plotly_dash/dash_wrapper.py

@@ -252,7 +252,7 @@ def get_asset_url(self, asset_name):
 
         #return self.as_dash_instance().get_asset_url(asset_name)
 
-class PseudoFlask:
+class PseudoFlask(Flask):
     'Dummy implementation of a Flask instance, providing stub functionality'
     def __init__(self):
         self.config = {}

django_plotly_dash/version.py

@@ -23,4 +23,4 @@
 
 '''
 
-__version__ = "0.9.12"
+__version__ = "0.9.13"