fix: icorrect concat directives

Author: Scrum

index.js

@@ -26,7 +26,7 @@ function postHTMLParser(html, options) {
     };
 
     function parserDirective(name, data) {
-        var directives = objectAssign(defaultDirectives, options.directives);
+        var directives = [].concat(defaultDirectives, options.directives || []);
         var last = bufArray.last();
 
         for (var i = 0; i < directives.length; i++) {