Headless test using puppeteer

[samarpanda]

Headless test using puppeteer

Created a basic node server which serves an index.html file. First-Input-delay.js file added to its head. Puppeteer loads this file & triggers mousedown event.

Todos

• [x] Puppeteer & node server configured to test user generated events
• [x] Travis configured to trigger the test for every change
• [x] Handle click & touchstart
• [x] Handle keydown & mousedown

@philipwalton Would like to get a first round of feedback on this. So, i can get this PR ready by next week.

Need some help to configure 3 point of todos.

[samarpanda]

@philipwalton Could you please review my PR?

[samarpanda]

@philipwalton Final review pending on this PR. Please pick this when you are available.