Enhance existing leaflet.js map to include choropleth layers

All of the below specs have to be fulfilled in order to receive payment: Prerequisites: - you will work with existing project located on github: [login to view URL], creating a new branch which will include changes (primarily to blob/master/Clustering/[login to view URL]) that can be merged back into main branch upon approval of work. - code written will utilise [login to view URL] library ([login to view URL]) and also compliant with bootstrap and html5 Details of work: - work will involve modifying an existing map in order to successfully display one of three possible layers over existing populated map, which includes basemap (drawn using [login to view URL]) AND points rendered using CartoDB SQL API ([login to view URL]) - each layer to be rendered will draw polygon data using Carto API (from self-hosted carto instance) joined to another table with demographic data which will indicate polygon colour - polygons will be rendered with a transparent choropleth fill (number of colour bins and colours used will be layer specific) - code will include option to select/deselect layers buttons located within an already populated leaflet-sidebar ([login to view URL]) window - solution employed will need to render layers quickly (200ms or faster)