Improve single message errors and testcase

Author: acrobat

lib/Github/HttpClient/Plugin/GithubExceptionThrower.php

@@ -81,6 +81,12 @@ public function doHandleRequest(RequestInterface $request, callable $next, calla
                                 break;
 
                             default:
+                                if (is_string($error)) {
+                                    $errors[] = $error;
+
+                                    break;
+                                }
+
                                 if (isset($error['message'])) {
                                     $errors[] = $error['message'];
                                 }

test/Github/Tests/HttpClient/Plugin/GithubExceptionThrowerTest.php

@@ -37,7 +37,7 @@ public function testHandleRequest(ResponseInterface $response, ExceptionInterfac
         if ($exception) {
             $this->expectException(get_class($exception));
             $this->expectExceptionCode($exception->getCode());
-            $this->expectExceptionMessage($exception->getMessage());
+            $this->expectExceptionMessageRegExp('/'.preg_quote($exception->getMessage(), '/').'$/');
         }
 
         $plugin->doHandleRequest(
@@ -210,7 +210,7 @@ public static function responseProvider()
                         ]
                     )
                 ),
-                'exception' => new \Github\Exception\ValidationFailedException('Validation Failed', 422),
+                'exception' => new \Github\Exception\ValidationFailedException('Validation Failed: We cannot delete an active deployment unless it is the only deployment in a given environment.', 422),
             ],
         ];
     }