Use filename as a unique identifier

Otherwise subsequent calls will always only return the template, that was loaded first. This is because Marco is using cached Templates by default.

lib/consolidate.js

@@ -1467,9 +1467,10 @@ exports.marko.render = function(str, options, fn) {
   return promisify(fn, function (fn) {
     var engine = requires.marko || (requires.marko = require('marko'));
     options.writeToDisk = !!options.cache;
+    options.filename = options.filename || 'string.marko';
 
     try {
-      var tmpl = cache(options) || cache(options, engine.load('string.marko', str, options));
+      var tmpl = cache(options) || cache(options, engine.load(options.filename, str, options));
       tmpl.renderToString(options, fn)
     } catch (err) {
       fn(err);