.travis.yml in rails_state_machine-1.1.3 vs .travis.yml in rails_state_machine-2.0.0

@@ -5,21 +5,33 @@
 before_script:
   - psql -c 'create database rails_state_machine_test;' -U postgres
   - mysql -e 'create database IF NOT EXISTS rails_state_machine_test;'
 
 install:
+  - gem install bundler:2.0.2
   # Replace default Travis CI bundler script with a version that doesn't
   # explode when lockfile doesn't match recently bumped version
   - bundle install --no-deployment --jobs=3 --retry=3 --path=${BUNDLE_PATH:-vendor/bundle}
 
 script: bundle exec rake current_rspec
 
-rvm:
-  - 2.3.7
-  - 2.4.4
-  - 2.5.1
+matrix:
+  include:
+    - rvm: 2.3.8
+      gemfile: Gemfile.5.1.pg
+    - rvm: 2.4.6
+      gemfile: Gemfile.5.1.pg
+    - rvm: 2.3.8
+      gemfile: Gemfile.5.2.pg
+    - rvm: 2.4.6
+      gemfile: Gemfile.5.2.pg
+    - rvm: 2.5.6
+      gemfile: Gemfile.5.2.pg
+    - rvm: 2.5.6
+      gemfile: Gemfile.6.0.pg
+    - rvm: 2.6.4
+      gemfile: Gemfile.6.0.pg
 
-gemfile:
-  - Gemfile.5.1.pg
-  - Gemfile.5.2.pg
-
 dist: trusty
+
+addons:
+  postgresql: 9.3