.travis.yml in symbolify-1.3.0 vs .travis.yml in symbolify-1.3.1

@@ -1,22 +1,22 @@
 sudo: false
 language: ruby
 
 rvm:
 - ruby-head
-- 2.4.1
-- 2.3.3
+- 2.5.1
+- 2.4.4
+- 2.3.7
 - 2.2
 - 2.1
 - 2.0
 - jruby-head
-- jruby-9.1.8.0
+- jruby-9.1.16.0
 
-cache:
-- bundler
-
 matrix:
   allow_failures:
     - rvm: jruby-head
     - rvm: ruby-head
+    - rvm: 2.2
+    - rvm: 2.1
     - rvm: 2.0
 #   fast_finish: true