Add workaround for Travis CI issue on Ruby 2.5

zorab47 · zorab47 · commit de0df9e9f337 · 2018-01-22T16:02:12.000-06:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,5 +1,9 @@
 language: ruby
 
+before_install:
+  # Workaround for https://github.com/travis-ci/travis-ci/issues/8969
+  - gem update --system
+
 rvm:
   - 2.2
   - 2.3
