.travis.yml in uswds-rails-1.6.3 vs .travis.yml in uswds-rails-1.6.4

@@ -1,14 +1,11 @@
 language: ruby
 cache: bundler
 rvm:
   - 2.2.9
-  - 2.3.6
-  - 2.4.3
-  - 2.5.0
-before_install:
-  - gem update --system
-  - gem update bundler
+  - 2.3.7
+  - 2.4.4
+  - 2.5.1
 before_script:
   - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
   - chmod +x ./cc-test-reporter
   - ./cc-test-reporter before-build
 after_success: