Fix .travis.yml (#41)

diff --git a/.travis.yml b/.travis.yml
index 140ce59..fc8e768 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,14 +5,8 @@
 
 dart_task:
   - test
-
-matrix:
-  include:
-    - dart: dev
-      dart_task: dartfmt
-  include:
-    - dart: dev
-      dart_task: dartanalyzer
+  - dartfmt
+  - dartanalyze
 
 # Only building master means that we don't run two builds for each pull request.
 branches: