.travis.yml in slavery-3.0.0 vs .travis.yml in slavery-4.0.0

@@ -1,13 +1,14 @@
 language: ruby
 
-rvm:
- - 2.2.2
- - 2.3.3
-
-gemfile:
-  - Gemfile
-  - gemfiles/rails3.2.gemfile
-  - gemfiles/rails4.gemfile
-  - gemfiles/rails4.2.gemfile
+matrix:
+  include:
+  - rvm: ruby-head
+    gemfile: Gemfile
+  - rvm: 2.5
+    gemfile: gemfiles/rails5.2.gemfile
+  - rvm: 2.5
+    gemfile: gemfiles/rails4.2.gemfile
+  - rvm: 2.2
+    gemfile: gemfiles/rails3.2.gemfile
 
 script: bundle exec rspec spec