Update .travis.yml
diff --git a/.travis.yml b/.travis.yml
index 979ab40..07e0e42 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,6 @@
 
 dart:
   - dev
-#  - stable
+  - stable
 
 script: ./tool/all_tests.sh