Change MultipartFile.fromFile to MultipartFile.fromPath in pkg/http.

pkg/http/test/utils.dart

Index: pkg/http/test/utils.dart
diff --git a/pkg/http/test/utils.dart b/pkg/http/test/utils.dart
index 4ffa195fd46b0511ae06bf93403800006b28ede1..8b404a581386cbaa2af8ba7c238a738b21af2d04 100644
--- a/pkg/http/test/utils.dart
+++ b/pkg/http/test/utils.dart
@@ -10,9 +10,9 @@ import 'dart:json' as json;
 import 'dart:uri';
 
 import 'package:unittest/unittest.dart';
-import 'package:http/src/byte_stream.dart';
-import 'package:http/http.dart' as http;
-import 'package:http/src/utils.dart';
+import '../lib/src/byte_stream.dart';
+import '../lib/http.dart' as http;
+import '../lib/src/utils.dart';
 
 /// The current server instance.
 HttpServer _server;