prepare stable, null-safe v2 (dart-lang/web_socket_channel#155)

pkgs/web_socket_channel/CHANGELOG.md

diff --git a/pkgs/web_socket_channel/CHANGELOG.md b/pkgs/web_socket_channel/CHANGELOG.md
index 261415e..e099326 100644
--- a/pkgs/web_socket_channel/CHANGELOG.md
+++ b/pkgs/web_socket_channel/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 2.0.0-dev
+## 2.0.0
 
 - Support null safety.
 - Require Dart 2.12.

pkgs/web_socket_channel/pubspec.yaml

diff --git a/pkgs/web_socket_channel/pubspec.yaml b/pkgs/web_socket_channel/pubspec.yaml
index 8b8339a..9454c65 100644
--- a/pkgs/web_socket_channel/pubspec.yaml
+++ b/pkgs/web_socket_channel/pubspec.yaml
@@ -1,5 +1,5 @@
 name: web_socket_channel
-version: 2.0.0-dev
+version: 2.0.0
 
 description: >-
   StreamChannel wrappers for WebSockets. Provides a cross-platform
@@ -18,8 +18,3 @@
 dev_dependencies:
   pedantic: ^1.10.0
   test: ^1.16.0
-
-dependency_overrides:
-  # Need to update dependencies on these to allow v2 of this package
-  shelf_web_socket: ^0.2.4
-  test: ^1.16.0