bump uglify-js and add mocha
bump uglify-js and add mocha

Esri/esri-leaflet,RuXxar/esri-leaflet,patrickarlt/esri-leaflet,RuXxar/esri-leaflet,Esri/esri-leaflet,patrickarlt/esri-leaflet,patrickarlt/esri-leaflet,RuXxar/esri-leaflet,Esri/esri-leaflet