- adding masonry and numColumns options to Tiles (fills masonry-style layout with cards of varying height in order from left-to-right) - updating Tiles.js to use es6 syntax and classnames module.
- adding masonry and numColumns options to Tiles (fills masonry-style layout with cards of varying height in order from left-to-right)
- updating Tiles.js to use es6 syntax and classnames module.

Signed-off-by: Jackie Wijaya <a1bd68b596538eefe75c18d0f33235ef95568d46@webmocha.com>

linde12/grommet,codeswan/grommet,codeswan/grommet,HewlettPackard/grommet,grommet/grommet,HewlettPackard/grommet,kylebyerly-hp/grommet,nickjvm/grommet,grommet/grommet,grommet/grommet,HewlettPackard/grommet,nickjvm/grommet