.travis.yml in vagrant-notify-0.5.6 vs .travis.yml in vagrant-notify-0.6.0

@@ -1,4 +1,6 @@
 language: ruby
 bundler_args: --without development
 rvm:
-  - 2.3.3
+  - 2.7.1
+before_install:
+    - gem install bundler