.travis.yml in characteristics-0.5.2 vs .travis.yml in characteristics-0.6.0

@@ -1,16 +1,16 @@
 sudo: false
 language: ruby
 
 rvm:
 - ruby-head
-- 2.4.0
-- 2.3.3
+- 2.4.1
+- 2.3.4
 - 2.2
 - 2.1
 - 2.0
 - jruby-head
-- jruby-9.1.7.0
+- jruby-9.1.8.0
 
 cache:
 - bundler
 
 matrix: