D3 visualization fundamentals hello world app

this project is to introduce D3 data visualization fundamentals at hello world app

Run the app locally

1. Install Node.js
2. Download and extract the starter code from the Bluemix UI
3. cd into the app directory
4. Run npm install to install the app's dependencies
5. Run npm start to start the app
6. Access the running app in a browser at http://localhost:6001