change allow failures for rubies

Author: hsbt

.travis.yml

@@ -14,13 +14,11 @@ rvm:
 - 2.2.5
 - 2.3.1
 - ruby-head
-- jruby-1.7.25
-- jruby-9.1.0.0
 - rbx-2
 - rbx
 script: rake test
 matrix:
   allow_failures:
-    - rvm: 1.8.7
+    - rvm: jruby-1.7.25
+    - rvm: jruby-9.1.0.0
     - rvm: rbx-2
-    - rvm: ruby-head