fix lint

Author: itsdiay

lib/index.js

@@ -21,7 +21,7 @@ module.exports = (options = {}) => {
       let subtree;
       let source;
       let locals = false;
-      let delimiters =  options.delimiters || ['{{','}}'];
+      const delimiters = options.delimiters || ['{{', '}}'];
 
       if (src) {
         src = path.resolve(options.root, src);