.travis.yml in docdata-order-1.0.1 vs .travis.yml in docdata-order-1.0.2

@@ -1,7 +1,11 @@
 language: ruby
 sudo: false
 cache: bundler
+before_install:
+  - gem update --system
+  - gem install bundler
 rvm:
-  - 2.2.9
-  - 2.3.6
-  - 2.4.3
+  - 2.2.10
+  - 2.3.8
+  - 2.4.5
+  - 2.5.3