.travis.yml in build-files-1.1.0 vs .travis.yml in build-files-1.2.0

@@ -8,7 +8,8 @@
   - ruby-head
   - rbx-2
 env: COVERAGE=true
 matrix:
   allow_failures:
-    - rvm: "rbx-2"
+    - rvm: rbx-2
+    - rvm: ruby-head