docs(readme): Update readme

Author: unicodeveloper

README.md

@@ -111,6 +111,10 @@ MERCHANT_EMAIL=unicodeveloper@gmail.com
 
 Set up routes and controller methods like so:
 
+Note: Make sure you have `/payment/callback` registered in Paystack Dashboard [https://dashboard.paystack.co/#/settings/developer](https://dashboard.paystack.co/#/settings/developer) like so:
+
+![payment-callback](https://cloud.githubusercontent.com/assets/2946769/12746754/9bd383fc-c9a0-11e5-94f1-64433fc6a965.png)
+
 ```php
 Route::post('/pay', 'PaymentController@redirectToGateway')->name('pay');
 Route::get('/payment/callback', 'PaymentController@handleGatewayCallback');
@@ -147,8 +151,9 @@ class PaymentController extends Controller
     {
         $paymentDetails = Paystack::getPaymentData();
 
-        dd($paymentDetails); // Now you have the payment details,
-        // you can store the authorisation code in your db to allow for recurrent subscriptions
+        dd($paymentDetails);
+        // Now you have the payment details,
+        // you can store the authorization_code in your db to allow for recurrent subscriptions
         // you can then redirect or do whatever you want
     }
 }

src/PaystackServiceProvider.php

@@ -1,6 +1,5 @@
 <?php
 
-
 /*
  * This file is part of the Laravel Paystack package.
  *

tests/PaystackTest.php

@@ -16,11 +16,5 @@
 
 class PaystackTest extends PHPUnit_Framework_TestCase
 {
-    /**
-     * Test that true does in fact equal true
-     */
-    public function testTrueIsTrue()
-    {
-        $this->assertTrue(true);
-    }
+
 }