Adds the geolocation icon and functionality.

Takes the example from
https://www.mapbox.com/mapbox.js/example/v1.0.0/leaflet-locatecontrol/.

Adds the typical arrow icon. If you click or tap it will zoom to current
location and show the location dot.
newest data
moving target pop to the top
more cleanup of populations data
Merge pull request #119 from ohnorobo/gh-pages

newer data and faceting over populations
using cities instead of counties in addresses
using cities instead of counties in addresses
switching properties from opject to list
adding directions element to infobox
fixing travis style issues
starting to fix tests
fixing tests to match config
Merge pull request #122 from ohnorobo/directions

Directions
moving L.Control.Geolocate
adding Locate dependency in testing requirements
adding control shim to runner.js
fix mock map interaction
Merge pull request #123 from ohnorobo/geolocate

Geolocate
some basic stuff for searching through fixtures

Refs #69