.travis.yml in directory_diff-0.5.0 vs .travis.yml in directory_diff-0.6.0

@@ -6,9 +6,9 @@
   - 2.4.4
   - 2.5.1
 gemfile:
   - gemfiles/activerecord_5.1.gemfile
   - gemfiles/activerecord_5.2.gemfile
-before_install: gem install bundler -v 1.11.2
+before_install: gem install bundler -v 2.4.22
 script:
   - bundle exec rake db:create
   - bundle exec rake spec