.travis.yml in strong_migrations-0.1.6 vs .travis.yml in strong_migrations-0.1.7

@@ -1,13 +1,12 @@
 language: ruby
 rvm:
-  - 2.3.1
+  - 2.4.1
 gemfile:
   - Gemfile
-  - test/gemfiles/activerecord32.gemfile
-  - test/gemfiles/activerecord40.gemfile
-  - test/gemfiles/activerecord41.gemfile
+  - test/gemfiles/activerecord50.gemfile
+  - test/gemfiles/activerecord42.gemfile
 script: bundle exec rake test
 before_script:
   - psql -c 'create database strong_migrations_test;' -U postgres
   - mysql -e 'create database strong_migrations_test;'
 notifications:
@@ -16,6 +15,6 @@
     on_failure: change
 matrix:
   include:
     - gemfile: test/gemfiles/mysql2.gemfile
       env: ADAPTER=mysql2
-      rvm: 2.2
+      rvm: 2.4.1