Add ruby 2.4.0 and jruby 9.1.7.0 to travis configuration

Author: Ivo Anjo

.travis.yml

@@ -10,10 +10,11 @@ matrix:
     - rvm: 2.3.1
     - rvm: 2.3.0
     - rvm: 2.2.5
+    - rvm: 2.4.0
     - rvm: rbx-2
     - rvm: ruby-head
     - rvm: jruby-head
-    - rvm: jruby-9.1.6.0
+    - rvm: jruby-9.1.7.0
   allow_failures:
     - rvm: ruby-head
     - rvm: jruby-head