Update .travis.yml

.travis.yml

@@ -1,12 +1,10 @@
-# We want to use the KVM-based system, so require sudo
-sudo: required
 services:
   - docker
 
 before_install:
   - git clone --depth=1 https://github.com/discourse/discourse-plugin-ci
 
-install: true # Prevent travis doing bundle install
+install: true
 
 script:
   - discourse-plugin-ci/script.sh