Add new badges to README.md

Next to title:
* Added "version" badge.
* Added "gittip" badge.

Underneath title:
* Added "node" badge.
* Added "grunt" badge.
* Updated "build" badge (travis-ci) to use SVG instead of PNG.
* Added "dependency" badges (david-dm).
* Added "code-climate" badge.
Merge pull request #177 from markcarver/badges

Add new badges to README.md