.travis.yml in shallow_attributes-0.9.4 vs .travis.yml in shallow_attributes-0.9.5

@@ -1,12 +1,15 @@
 language: ruby
 sudo: false
 cache: bundler
-before_install: gem install bundler -v 1.11.2
+before_install:
+  - gem uninstall -v '>= 2' -i $(rvm gemdir)@global -ax bundler || true
+  - gem install bundler -v '< 2'
 rvm:
-  - 2.2.5
   - 2.3.1
   - 2.4.0
+  - 2.5.0
+  - 2.6.0
   - jruby-head
   - rbx-2
   - ruby-head
 matrix:
   allow_failures: