.travis.yml in pg_ha_migrations-1.0.0 vs .travis.yml in pg_ha_migrations-1.1.0

@@ -4,6 +4,8 @@
   - 2.4
 services:
   - postgresql
 addons:
   postgresql: "9.6"
-before_install: gem install bundler -v 1.15.4
+before_install:
+  - gem uninstall -v '>= 2' -i $(rvm gemdir)@global -ax bundler || true
+  - gem install bundler -v 1.15.4