.travis.yml in shirinji-0.0.3 vs .travis.yml in shirinji-0.0.4

- old
+ new

@@ -1,5 +1,14 @@
 sudo: false
 language: ruby
 rvm:
-  - 2.3.4
-before_install: gem install bundler -v 1.16.0
+  - 2.4.0
+  - 2.4.1
+  - 2.4.2
+  - 2.4.3
+  - 2.4.4
+  - 2.5.0
+  - 2.5.1
+  - 2.5.2
+  - 2.5.3
+  - 2.6.0
+before_install: gem install bundler -v 1.16.6