.travis.yml in backlog_kit-0.17.0 vs .travis.yml in backlog_kit-0.18.0

@@ -1,12 +1,12 @@
 language: ruby
 rvm:
   - 2.0.0
   - 2.1.10
   - 2.2.10
-  - 2.3.7
-  - 2.4.4
-  - 2.5.1
+  - 2.3.8
+  - 2.4.5
+  - 2.5.3
   - ruby-head
 before_install:
   - gem update --system
   - gem update bundler
 env: