add Apps endpoint get /users/:username/installation

Author: jamiehuson

lib/Github/Api/Apps.php

@@ -93,6 +93,19 @@ public function getInstallationForRepo($owner, $repo)
         return $this->get('/repos/'.rawurldecode($owner).'/'.rawurldecode($repo).'/installation');
     }
 
+    /**
+     * Get an installation of the application for a user
+     *
+     * @link https://developer.github.com/v3/apps/#get-a-user-installation
+     *
+     * @param $username
+     * @return array
+     */
+    public function getInstallationForUser($username)
+    {
+        return $this->get('/users/'.rawurldecode($username).'/installation');
+    }
+
     /**
      * Delete an installation of the application
      *

test/Github/Tests/Api/AppTest.php

@@ -88,6 +88,22 @@ public function shouldGetInstallationForRepo()
         $this->assertEquals($result, $api->getInstallationForRepo('MyOrg', 'MyRepo'));
     }
 
+    /**
+     * @test
+     */
+    public function shouldGetInstallationForUser()
+    {
+        $result = ['installation1'];
+
+        $api = $this->getApiMock();
+        $api->expects($this->once())
+            ->method('get')
+            ->with('/users/octocat/installation')
+            ->willReturn($result);
+
+        $this->assertEquals($result, $api->getInstallationForUser('octocat'));
+    }
+
     /**
      * @test
      */