Fix sourcemap after changes in source_span

BUG=
R=nweiz@google.com

Review URL: https://codereview.chromium.org//1035343002
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 531a6d0..7477655 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.10.0+2
+
+* Fix analyzer error (FileSpan has a new field since `source_span` 1.1.1)
+
 ## 0.10.0+1
 
 * Remove an unnecessary warning printed when the "file" field is missing from a
diff --git a/lib/src/source_map_span.dart b/lib/src/source_map_span.dart
index 20eb17a..b70bdfe 100644
--- a/lib/src/source_map_span.dart
+++ b/lib/src/source_map_span.dart
@@ -44,6 +44,7 @@
   FileLocation get start => _inner.start;
   FileLocation get end => _inner.end;
   String get text => _inner.text;
+  String get context => _inner.context;
   Uri get sourceUrl => _inner.sourceUrl;
   int get length => _inner.length;
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 1d94c32..200f8f8 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,12 +1,12 @@
 name: source_maps
-version: 0.10.0+1
+version: 0.10.0+2
 author: Dart Team <misc@dartlang.org>
 description: Library to programmatically manipulate source map files.
 homepage: http://github.com/dart-lang/source_maps
 dependencies:
-  path: '>=1.2.0 <2.0.0'
-  source_span: '>=1.0.0 <2.0.0'
+  path: ^1.2.0
+  source_span: ^1.1.1
 environment:
-  sdk: '>=0.8.10+6 <2.0.0'
+  sdk: '>=1.8.0 <2.0.0'
 dev_dependencies:
-  unittest: '>=0.9.0 <0.10.0'
+  unittest: '>=0.9.0 <0.12.0'