unconstrain dart
diff --git a/pkgs/yaml/.travis.yml b/pkgs/yaml/.travis.yml
index e982192..e0a5b90 100644
--- a/pkgs/yaml/.travis.yml
+++ b/pkgs/yaml/.travis.yml
@@ -1,7 +1,6 @@
 language: dart
 
 dart:
-  - 2.4.0
   - dev
 
 dart_task: