Switch to using Posix.join

Author: Kyle Swanson

libs/url/builder.js

@@ -62,12 +62,10 @@ module.exports.buildURL = function(opts) {
         if(transformationUtils.addAsQueryParameter(opts) || isSrcParameterUsedForURL) {
             queryParameters.set(TRANSFORMATION_PARAMETER, transformationString);   
         } else {
-            urlObject.pathname = path.join(
+            urlObject.pathname = path.posix.join(
                                     [TRANSFORMATION_PARAMETER, transformationString].join(transformationUtils.getChainTransformDelimiter()),
                                     urlObject.pathname
-                                // Fix for Windows pathnames having backslashes instead of forward slashes. 
-                                // TODO: Replace path.join with a different library.
-                                ).replace("\\", "/")
+                                 )
         }
     }