Remove dartlang.org links (#395)

Author: kevmoo

.github/ISSUE_TEMPLATE/1-FAILING_CONNECTION.md

@@ -16,8 +16,8 @@ This package is a wrapper around the HttpClient from dart:io and HttpRequest
 from dart:html. Before filing a bug here verify that the issue is not surfaced
 when using those interfaces directly.
 
-https://api.dartlang.org/stable/dart-io/HttpClient-class.html
-https://api.dartlang.org/stable/dart-html/HttpRequest-class.html
+https://api.dart.dev/stable/dart-io/HttpClient-class.html
+https://api.dart.dev/stable/dart-html/HttpRequest-class.html
 
 # Common problems:
 

test/utils.dart

@@ -9,7 +9,7 @@ import 'package:http_parser/http_parser.dart';
 import 'package:test/test.dart';
 
 /// A dummy URL for constructing requests that won't be sent.
-Uri get dummyUrl => Uri.parse('http://dartlang.org/');
+Uri get dummyUrl => Uri.parse('http://dart.dev/');
 
 /// Removes eight spaces of leading indentation from a multiline string.
 ///