Update leaflet master readme with mention to 1.0.0-b1 dependency.
Update leaflet master readme with mention to 1.0.0-b1 dependency.

benstoltz/esri-leaflet,RuXxar/esri-leaflet,PaulCrickard/esri-leaflet,Esri/esri-leaflet,SamDrummond/esri-leaflet,SamDrummond/esri-leaflet,venividimap/esri-leaflet,stephanienelson/esri-leaflet,SamDrummond/esri-leaflet,Esri/esri-leaflet,PaulCrickard/esri-leaflet,patrickarlt/esri-leaflet,venividimap/esri-leaflet,RuXxar/esri-leaflet,patrickarlt/esri-leaflet,simplot/esri-leaflet,patrickarlt/esri-leaflet,benstoltz/esri-leaflet,simplot/esri-leaflet,venividimap/esri-leaflet,PaulCrickard/esri-leaflet,stephanienelson/esri-leaflet,RuXxar/esri-leaflet,benstoltz/esri-leaflet,stephanienelson/esri-leaflet,Esri/esri-leaflet,simplot/esri-leaflet