Unable to create Custom Kibana Visualisation

Hi clintandrewhall,

I tried to follow the steps mentioned here

however i am getting below error in console, when trying to click on 'Visualize' in Kibana.

Uploaded the code to git repository for reference.
https://github.com/aditya-deshpadne/custom_visualization/blob/master/test_vis.zip

Similar discussions found on forum for reference : Error when building new visualization factory

Any pointers to resolve the issue is really appreciated.

Thank you,
Aditya