fix: bump version to match current

index.js had not been updated to relfect the currently released version
which was affecting out internal reporting for this version of the
library. This commit fixes the version number.

src/imgix.js

@@ -2,7 +2,7 @@ var ImgixTag = require('./ImgixTag.js'),
   util = require('./util.js'),
   defaultConfig = require('./defaultConfig');
 
-var VERSION = '3.4.2';
+var VERSION = '3.5.0';
 
 global.imgix = {
   init: function (opts) {