Fix issue in lack of decorators

Author: mgechev

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ng2lint",
-  "version": "0.0.3",
+  "version": "0.0.4",
   "description": "A set of linters for Angular 2 applications, following https://github.com/mgechev/angular2-style-guide.",
   "main": "index.js",
   "scripts": {

src/selectorNameBase.ts

@@ -49,7 +49,7 @@ class SelectorNameValidatorWalker extends Lint.RuleWalker {
   }
 
   visitClassDeclaration(node: ts.ClassDeclaration) {
-    node.decorators.forEach(this.validateDecorator.bind(this, node.name.text));
+    (node.decorators || []).forEach(this.validateDecorator.bind(this, node.name.text));
     super.visitClassDeclaration(node);
   }