drop unneeded dep

Author: kevmoo

pkgs/google_cloud/lib/src/serving/json_request_checking.dart

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import 'dart:io';
-import 'package:http_parser/http_parser.dart';
+import 'package:http/http.dart' show MediaType;
 import 'package:meta/meta.dart';
 
 /// Evaluates whether to send a JSON response based on request headers.

pkgs/google_cloud/pubspec.yaml

@@ -11,7 +11,6 @@ environment:
 dependencies:
   collection: ^1.19.0
   http: ^1.1.0
-  http_parser: ^4.0.0
   io: ^1.0.3
   meta: ^1.18.1
   shelf: ^1.4.0