Test on oldest supported SDK (#37)

diff --git a/.gitignore b/.gitignore
index 3cc62a7..49ce72d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,11 +1,3 @@
-.buildlog
-.DS_Store
-.idea
 .dart_tool/
-.project
-.settings
-build/
-doc/api/
-packages
-pubspec.lock
 .packages
+pubspec.lock
diff --git a/.travis.yml b/.travis.yml
index 3c087ca..b46f900 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,9 @@
 language: dart
 dart:
+  - 2.0.0
   - dev
+
 script: ./tool/travis.sh
-dist: trusty
-sudo: false
 
 branches:
   only:
diff --git a/codereview.settings b/codereview.settings
deleted file mode 100644
index 2b2da2d..0000000
--- a/codereview.settings
+++ /dev/null
@@ -1,3 +0,0 @@
-CODE_REVIEW_SERVER: https://chromiumcodereview.appspot.com/
-VIEW_VC: https://github.com/dart-lang/cli_util/commit/
-CC_LIST: reviews@dartlang.org
diff --git a/pubspec.yaml b/pubspec.yaml
index db6573a..5e06af1 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -5,7 +5,7 @@
 homepage: https://github.com/dart-lang/cli_util
 
 environment:
-  sdk: '>=2.0.0-dev.55.0 <3.0.0'
+  sdk: '>=2.0.0 <3.0.0'
 
 dependencies:
   path: '>=1.0.0 <2.0.0'