Added the attempts property and assigned it to the error object returned when a network error occurs

Author: vioint

README.md

@@ -25,7 +25,7 @@ Install with [npm](https://npmjs.org/package/requestretry).
 
 ## Usage
 
-Request-retry is a drop-in replacement for [request](https://github.com/mikeal/request) but adds two new options `maxAttempts` and `retryDelay`. It also adds one property to the response, `attempts`. It supports callbacks or promises.
+Request-retry is a drop-in replacement for [request](https://github.com/mikeal/request) but adds two new options `maxAttempts` and `retryDelay`. It also adds one property to the response (or the error object, upon a network error), `attempts`. It supports callbacks or promises.
 
 ### With callbacks
 

index.js

@@ -124,6 +124,8 @@ Request.prototype._tryUntilFail = function () {
   this._req = Request.request(this.options, function (err, response, body) {
     if (response) {
       response.attempts = this.attempts;
+    } else if (err) {
+      err.attempts = this.attempts;
     }
     if (this.retryStrategy(err, response, body) && this.maxAttempts > 0) {
       this._timeout = setTimeout(this._tryUntilFail.bind(this), this.delayStrategy.call(this, err, response, body));