.travis.yml in ridgepole-0.7.1 vs .travis.yml in ridgepole-0.7.2.beta

@@ -4,13 +4,13 @@
 language: ruby
 cache:
   - bundler
   - apt
 rvm:
-  - 2.2.8
-  - 2.3.5
-  - 2.4.2
+  - 2.2.9
+  - 2.3.6
+  - 2.4.3
 before_install:
   - gem install bundler
 before_script:
   - sudo service mysql stop
   - sudo service postgresql stop
@@ -24,9 +24,10 @@
 script:
   - bundle exec rake
 gemfile:
   - gemfiles/activerecord_5.0.gemfile
   - gemfiles/activerecord_5.1.gemfile
+  - gemfiles/activerecord_5.2.gemfile
 env:
   matrix:
     - MYSQL56=1
     - MYSQL57=1
     - POSTGRESQL=1