.travis.yml in active_admin_sidebar-1.1.0 vs .travis.yml in active_admin_sidebar-1.2.0

@@ -1,19 +1,21 @@
 sudo: required
+
 language: ruby
+
 addons:
   chrome: stable
 
-before_install: gem install bundler -v 1.17.1
+before_install:
+  - gem uninstall -v '>= 2' -i $(rvm gemdir)@global -ax bundler || true
+  - gem install bundler -v '< 2'
 
 script: bundle exec rspec
 
 env:
   matrix:
     - RAILS=5.1.6 AA=1.1.0
-    - RAILS=5.1.6 AA=1.2.1
-    - RAILS=5.2.1 AA=1.3.1
-    - RAILS=5.2.1 AA=1-4-stable
+    - RAILS=5.2.1 AA=1.4.0
 
 rvm:
-  - 2.3
-  - 2.5
+  - 2.4
+  - 2.6