Add lat/lng as mappable column keys (#77)

README.md

@@ -280,7 +280,7 @@ SELECT gender, zip_code, COUNT(*) FROM users GROUP BY 1, 2
 
 ### Maps
 
-Columns named `latitude` and `longitude` or `lat` and `lon` - [Example](https://blazerme.herokuapp.com/queries/15-map)
+Columns named `latitude` and `longitude` or `lat` and `lon` or `lat` and `lng` - [Example](https://blazerme.herokuapp.com/queries/15-map)
 
 ```sql
 SELECT name, latitude, longitude FROM cities

app/controllers/blazer/queries_controller.rb

@@ -204,7 +204,7 @@ module Blazer
       @linked_columns = @data_source.linked_columns
 
       @markers = []
-      [["latitude", "longitude"], ["lat", "lon"]].each do |keys|
+      [["latitude", "longitude"], ["lat", "lon"], ["lat", "lng"]].each do |keys|
         lat_index = @columns.index(keys.first)
         lon_index = @columns.index(keys.last)
         if lat_index && lon_index