.travis.yml in whatsup_github-0.3.1 vs .travis.yml in whatsup_github-0.4.0

@@ -1,5 +1,5 @@
 ---
 sudo: false
 language: ruby
 cache: bundler
-before_install: gem install bundler -v 1.17.3
+before_install: gem install bundler -v 2.2.15