.travis.yml in ios_toolchain-0.3.1 vs .travis.yml in ios_toolchain-0.3.2

@@ -1,5 +1,5 @@
 sudo: false
 language: ruby
 rvm:
   - 2.4.0
-before_install: gem install bundler -v 1.14.3
+before_install: gem install bundler -v 2.0.1