Update build files.

Author: jheer

vega.js

@@ -21,7 +21,7 @@ function (d3, topojson) {
 //---------------------------------------------------
 
   var vg = {
-    version:  "1.5.1", // semantic versioning
+    version:  "1.5.4", // semantic versioning
     d3:       d3,      // stash d3 for use in property functions
     topojson: topojson // stash topojson similarly
   };