Try slightly older ruby versions?

Author: kpaulisse

.travis.yml

@@ -13,9 +13,9 @@ matrix:
     - rvm: 2.4
       env: RUBOCOP_TEST="true" RSPEC_TEST="true"
     # Build with older ruby versions
-    - rvm: 2.3
+    - rvm: 2.3.2
       env: RUBOCOP_TEST="false" RSPEC_TEST="true"
-    - rvm: 2.2
+    - rvm: 2.2.3
       env: RUBOCOP_TEST="false" RSPEC_TEST="true"
     - rvm: 2.1
       env: RUBOCOP_TEST="false" RSPEC_TEST="true"