Merge pull request dart-lang/package_config#4 from dart-lang/sdk_constraint_bump

SDK constraint bump to pickup Uri.normalizePath().
diff --git a/pkgs/package_config/pubspec.yaml b/pkgs/package_config/pubspec.yaml
index b0f2d8f..7494fdd 100644
--- a/pkgs/package_config/pubspec.yaml
+++ b/pkgs/package_config/pubspec.yaml
@@ -5,7 +5,7 @@
 homepage: https://github.com/dart-lang/package_config
 
 environment:
-  sdk: '>=1.0.0 <2.0.0'
+  sdk: '>=1.11.0-dev.0.0 <2.0.0'
 
 dev_dependencies:
   test: '>=0.12.0 <0.13.0'