add existing checks to repo as described in the docs

Author: Leon Husmann

lib/Github/Api/Repo.php

@@ -2,6 +2,7 @@
 
 namespace Github\Api;
 
+use Github\Api\Repository\Checks;
 use Github\Api\Repository\Collaborators;
 use Github\Api\Repository\Comments;
 use Github\Api\Repository\Commits;
@@ -682,4 +683,16 @@ public function transfer($username, $repository, $newOwner, $teamId = [])
 
         return $this->post('/repos/'.rawurldecode($username).'/'.rawurldecode($repository).'/transfer', ['new_owner' => $newOwner, 'team_id' => $teamId]);
     }
+
+    /**
+     * Manage the checks of a repository.
+     *
+     * @link https://developer.github.com/v3/checks
+     *
+     * @return Checks
+     */
+    public function checks()
+    {
+        return new Checks($this->client);
+    }
 }

test/Github/Tests/Api/RepoTest.php

@@ -607,6 +607,16 @@ public function shouldTransferRepository()
         $this->assertEquals($expectedArray, $api->transfer('KnpLabs', 'php-github-api', 'github', [1234, 1235]));
     }
 
+    /**
+     * @test
+     */
+    public function shouldGetChecksApiObject()
+    {
+        $api = $this->getApiMock();
+
+        $this->assertInstanceOf(\Github\Api\Repository\Checks::class, $api->checks());
+    }
+
     /**
      * @return string
      */