fix findById return type, add npm version badge to readme

Author: matthewwolfe

README.md

@@ -1,6 +1,7 @@
 # active-record-js
 
 [![Build Status](https://travis-ci.com/matthewwolfe/active-record-js.svg?branch=master)](https://travis-ci.com/matthewwolfe/active-record-js)
+[![npm version](https://badge.fury.io/js/active-record-js.svg)](https://badge.fury.io/js/active-record-js)
 
 A Node.JS Active Record implementation, heavily influenced by Laravel's eloquent.
 

src/model/Model.ts

@@ -113,7 +113,7 @@ class Model implements HasAttributes, HasRelationships, HasTimestamps, HidesAttr
         return false;
     }
 
-    public static async findById(id: number): Promise<Model>
+    public static async findById(id: number): Promise<any>
     {
         return new this().newModelQuery().setIsFirst(true).where('id', '=', id).get();
     }