Support html2canvas v1.0.0 with promise-based call

Author: eKoopmans

src/index.js

@@ -50,12 +50,13 @@ var html2pdf = function(source, opt) {
 
   // Render the canvas and pass the result to makePDF.
   var onRendered = opt.html2canvas.onrendered || function() {};
-  opt.html2canvas.onrendered = function(canvas) {
+  delete opt.html2canvas.onrendered;
+  var done = function(canvas) {
     onRendered(canvas);
     document.body.removeChild(overlay);
     html2pdf.makePDF(canvas, pageSize, opt);
-  }
-  html2canvas(container, opt.html2canvas);
+  };
+  html2canvas(container, opt.html2canvas).then(done);
 };
 
 html2pdf.parseInput = function(source, opt) {