fixes #13 POST geojson was not working

Author: jperelli

lib/lib.js

@@ -27,7 +27,7 @@ function replacefiles(str) {
 module.exports = function(options) {
   return new Promise(function(resolve, reject) {
     options = options || {};
-    options.geojson = options.geojson || '';
+    options.geojson = (options.geojson && (typeof options.geojson === 'string' ? options.geojson : JSON.stringify(options.geojson))) || '';
     options.height = options.height || 600;
     options.width = options.width || 800;
     options.center = options.center || '';