.travis.yml in store_attribute-0.5.2 vs .travis.yml in store_attribute-0.5.3

@@ -10,9 +10,11 @@
 
 matrix:
   include:
     - rvm: 2.4.1
       gemfile: gemfiles/rails5.gemfile
+    - rvm: 2.6.2
+      gemfile: gemfiles/rails6.gemfile
     - rvm: ruby-head
       gemfile: gemfiles/railsmaster.gemfile
   allow_failures:
     - rvm: ruby-head
       gemfile: gemfiles/railsmaster.gemfile