Fix package.json `main` field

[mightydes]

For now used:

  "main": [
    "angularjs-color-picker.js",
    "angularjs-color-picker.css"
  ]

source

For properly work with, for example, browserify
should be:

  "main": "angularjs-color-picker.js"

https://docs.npmjs.com/files/package.json#main

Do you need a pull request for it?

[ruhley]

Merged your pull request. 👍