.travis.yml in carrierwave-base64-2.8.1 vs .travis.yml in carrierwave-base64-2.9.0

@@ -1,12 +1,12 @@
 language: ruby
 
 rvm:
- - 2.2.10
- - 2.3.8
- - 2.4.5
- - 2.5.2
+ - 2.4.9
+ - 2.5.7
+ - 2.6.5
+ - 2.7.0
  - ruby-head
  - jruby-head
 
 matrix:
   allow_failures:
@@ -15,9 +15,13 @@
 
 gemfile:
   - Gemfile
 
 sudo: false
+
+before_install:
+  - gem update --system
+  - gem update bundler
 
 script:
   - bundle exec rspec
   - bundle exec rubocop