Remove upper case constants (#6)

diff --git a/.travis.yml b/.travis.yml
index 73833e5..dc8b4f9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,8 +2,6 @@
 
 dart:
   - dev
-  - stable
-
 dart_task:
   - test
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d85c3d0..a6d8a92 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.2.2+1
+
+* Updated SDK version to 2.0.0-dev.17.0
+
 ## 0.2.2
 
 * Stop using comment-based generic syntax.
diff --git a/lib/src/web_socket_handler.dart b/lib/src/web_socket_handler.dart
index 05b7bb4..e5d4bed 100644
--- a/lib/src/web_socket_handler.dart
+++ b/lib/src/web_socket_handler.dart
@@ -66,7 +66,7 @@
 
     var protocol = _chooseProtocol(request);
     request.hijack((channel) {
-      var sink = UTF8.encoder.startChunkedConversion(channel.sink);
+      var sink = utf8.encoder.startChunkedConversion(channel.sink);
       sink.add("HTTP/1.1 101 Switching Protocols\r\n"
           "Upgrade: websocket\r\n"
           "Connection: Upgrade\r\n"
diff --git a/pubspec.yaml b/pubspec.yaml
index 73bc490..3b80906 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: shelf_web_socket
-version: 0.2.2
+version: 0.2.2+1
 author: "Dart Team <misc@dartlang.org>"
 homepage: http://github.com/dart-lang/shelf_web_socket
 description: >
@@ -12,4 +12,4 @@
   http: ">=0.10.0 <0.12.0"
   test: "^0.12.0"
 environment:
-  sdk: ">=1.21.0 <2.0.0"
+  sdk: ">=2.0.0-dev.17.0 <2.0.0"