Add commits endpoint for Gists

doc/gists.md

@@ -33,6 +33,12 @@ $gists = $github->api('gists')->all();
 $gist = $github->api('gists')->show(1);
 ```
 
+#### Get commits for a single gist
+
+```php
+$commits = $github->api('gists')->commits(1);
+```
+
 #### Create a gist
 
 ```php

lib/Github/Api/Gists.php

@@ -44,6 +44,11 @@ public function update($id, array $params)
         return $this->patch('gists/'.rawurlencode($id), $params);
     }
 
+    public function commits($id)
+    {
+        return $this->get('gists/'.rawurlencode($id).'/commits');
+    }
+
     public function fork($id)
     {
         return $this->post('gists/'.rawurlencode($id).'/fork');

test/Github/Tests/Api/GistsTest.php

@@ -52,6 +52,22 @@ public function shouldShowGist()
        $this->assertEquals($expectedArray, $api->show(123));
     }
 
+    /**
+     * @test
+     */
+    public function shouldShowCommits()
+    {
+        $expectedArray = array('id' => '123');
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('get')
+            ->with('gists/123/commits')
+            ->will($this->returnValue($expectedArray));
+
+       $this->assertEquals($expectedArray, $api->commits(123));
+    }
+
     /**
      * @test
      */