Switch pkg packages, pub, and dartdoc to use package: imports.

pkg/http/test/multipart_test.dart

Index: pkg/http/test/multipart_test.dart
diff --git a/pkg/http/test/multipart_test.dart b/pkg/http/test/multipart_test.dart
index b8210d2fbeb79c54dac867ce38cb0d1da77b2847..e7ea1e5335a2de550c49faaf1bae68d0a764553e 100644
--- a/pkg/http/test/multipart_test.dart
+++ b/pkg/http/test/multipart_test.dart
@@ -8,10 +8,10 @@ import 'dart:async';
 import 'dart:io';
 import 'dart:utf';
 
+import 'package:http/http.dart' as http;
+import 'package:http/src/utils.dart';
+import 'package:pathos/path.dart' as path;
 import 'package:unittest/unittest.dart';
-import '../../pathos/lib/path.dart' as path;
-import '../lib/http.dart' as http;
-import '../lib/src/utils.dart';
 
 import 'utils.dart';