drop esprima tree direct requirement

Author: Alexej Yaroshevich

lib/esprima-helpers.js

@@ -1,6 +1,5 @@
 module.exports = {
-    closestScopeNode : closestScopeNode,
-    treeIterator     : require('jscs/lib/tree-iterator')
+    closestScopeNode : closestScopeNode
 };
 
 var scopeNodeTypes = [

lib/rules/validate-jsdoc.js

@@ -59,6 +59,7 @@ module.exports.prototype = {
 
     check: function(file, errors) {
         patchNodesInFile(file);
+        this._iterate = file.iterate;
 
         var _this = this;
         var scopes = {
@@ -156,13 +157,13 @@ module.exports.prototype = {
         }
 
         var statements = [];
-        esprimaHelpers.treeIterator.iterate(node, function(n/*, parentNode, parentCollection*/) {
+        this._iterate(function(n) {
             if (n && n.type === 'ReturnStatement' && n.argument) {
                 if (node === esprimaHelpers.closestScopeNode(n)) {
                     statements.push(n.argument);
                 }
             }
-        });
+        }, node);
 
         node.jsdoc.returnStatements = statements;
         return statements;