.travis.yml in tdiary-style-gfm-0.4.1 vs .travis.yml in tdiary-style-gfm-0.5.0

@@ -1,9 +1,12 @@
 language: ruby
 rvm:
-  - 2.0.0
-  - 2.1
   - 2.2
-  - 2.3.0
+  - 2.3
+  - 2.4
   - ruby-head
+matrix:
+  allowed_failures:
+    - rvm: ruby-head
+
 before_install: gem update bundler
 script: bundle exec rake spec