Try without explicitly installing bundler?

kpaulisse · kpaulisse · commit 8a8477f4308e · 2018-08-14T23:00:27.000-05:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,7 +3,6 @@
 language: ruby
 install: true
 script: "script/cibuild"
-before_install: gem install bundler
 
 matrix:
   include:
