Pushing custom node_module while deploying on heroku

I am trying to deploy my node-express website on heroku. Everything works fine, but just one problem.

I have used express-stormpath as a dependency in my project, which i have customized(the views only).

When I deploy this to heroku, using git push heroku master, the node_module is ignored while uploading and all the modules are installed by heroku itself using npm. So my customization to the node module is not reflected at heroku.

I have tried this also: npm install private github repositories by dependency in package.json

Any suggestions on how to upload whole project including the node_modules to heroku?