upgrade to latest analyzer

pubspec.yaml

Index: pubspec.yaml
diff --git a/pubspec.yaml b/pubspec.yaml
index 350f19bbb884d59f1984b62f0bf77430f7087eac..3bb0b776af20bbd912ee4513443fa820e76e0d6b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -9,7 +9,7 @@ author: Dart Dev Compiler team <dev-compiler@dartlang.org>
 homepage: https://github.com/dart-lang/dev_compiler
 
 dependencies:
-  analyzer: ^0.27.2-alpha.1
+  analyzer: ^0.27.3-alpha.1
   barback: ^0.15.2+7
   code_transformers: ^0.4.0
   args: ^0.13.0
@@ -17,7 +17,7 @@ dependencies:
   crypto: ^0.9.0
   func: ^0.1.0
   html: ^0.12.0
-  js: ">=0.6.0 <0.7.0"
+  js: ^0.6.0
   logging: ">=0.9.2 <0.12.0"
   path: ^1.3.0
   pub_semver: ^1.1.0
@@ -31,7 +31,7 @@ dev_dependencies:
   # We pin a specific version to ensure everyone is formatting the code exactly
   # the same way. This is because any change in dart_style, even non-breaking
   # changes, may change the output format.
-  dart_style: 0.2.2
+  dart_style: 0.2.4
   test: ^0.12.0
   transformer_test: ^0.1.0
   webdriver: ^0.8.8