Added support for updating a label

Author: mnapoli

lib/Github/Api/Issue/Labels.php

@@ -38,6 +38,16 @@ public function deleteLabel($username, $repository, $label)
         return $this->delete('repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/labels/'.rawurlencode($label));
     }
 
+    public function update($username, $repository, $label, $newName, $color)
+    {
+        $params = array(
+            'name' => $newName,
+            'color' => $color,
+        );
+
+        return $this->patch('repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/labels/'.rawurlencode($label), $params);
+    }
+
     public function add($username, $repository, $issue, $labels)
     {
         if (is_string($labels)) {

test/Github/Tests/Api/Issue/LabelsTest.php

@@ -91,6 +91,23 @@ public function shouldDeleteLabel()
         $this->assertEquals($expectedValue, $api->deleteLabel('KnpLabs', 'php-github-api', 'foo'));
     }
 
+    /**
+     * @test
+     */
+    public function shouldUpdateLabel()
+    {
+        $expectedValue = array(array('name' => 'bar', 'color' => 'FFF'));
+        $data = array('name' => 'bar', 'color' => 'FFF');
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('patch')
+            ->with('repos/KnpLabs/php-github-api/labels/foo', $data)
+            ->will($this->returnValue($expectedValue));
+
+        $this->assertEquals($expectedValue, $api->update('KnpLabs', 'php-github-api', 'foo', 'bar', 'FFF'));
+    }
+
     /**
      * @test
      */