Gmaps multiple markers

![gmapsmorecolors](https://cloud.githubusercontent.com/assets/8646429/5302506/00b11b04-7baf-11e4-984a-4a8ecae73c32.gif)

[`each_with_index`](http://ruby-doc.org/core-2.1.5/Enumerable.html#method-i-each_with_index) is your friend