bump sdk constraint to 3.0.0

pkgs/package_config/CHANGELOG.md

diff --git a/pkgs/package_config/CHANGELOG.md b/pkgs/package_config/CHANGELOG.md
index a9ac0ec..8c179c7 100644
--- a/pkgs/package_config/CHANGELOG.md
+++ b/pkgs/package_config/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.0.4
+
+- Set max SDK version to <3.0.0.
+
 ## 1.0.3
 
 - Removed unneeded dependency constraint on SDK.

pkgs/package_config/pubspec.yaml

diff --git a/pkgs/package_config/pubspec.yaml b/pkgs/package_config/pubspec.yaml
index 56d44f5..c584681 100644
--- a/pkgs/package_config/pubspec.yaml
+++ b/pkgs/package_config/pubspec.yaml
@@ -1,11 +1,11 @@
 name: package_config
-version: 1.0.3
+version: 1.0.4
 description: Support for working with Package Resolution config files.
 author: Dart Team <misc@dartlang.org>
 homepage: https://github.com/dart-lang/package_config
 
 environment:
-  sdk: '>=2.0.0-dev <2.0.0'
+  sdk: '>=2.0.0-dev <3.0.0'
 
 dependencies:
   charcode: ^1.1.0