Update heading component (#175)
Update heading component (#175)

* Remove white space between defaultProps

* Replace rgb util with rgba util

* Use font weights from styles/typography

extraThin (100) is not a weight, but it was set to be the same as thin
(300) instead of being removed completely to maintain backwards
compatibility and prevent errors.

* Use colors from styles/colors

* Use media queries from styles/mq

* Remove settings.json

* Use font sizes from styles/typography

* Import PropTypes

* Use radium to merge conditional styles

lonelyplanet/backpack-ui,lonelyplanet/backpack-ui