.travis.yml in fix-let-0.1.2 vs .travis.yml in fix-let-0.1.3

@@ -5,13 +5,13 @@
   - gem install bundler
 script:
   - bundle exec rubocop
   - bundle exec rake test
 rvm:
-  - 2.2
   - 2.3.3
   - 2.4.0
   - 2.5.0
+  - 2.6.2
   - ruby-head
   - jruby-head
   - rbx-3
 matrix:
   allow_failures: