Do not install Riak CS, run Travis builds on Trusty containers

.travis.yml

@@ -5,7 +5,6 @@ rvm:
 services:
   - redis-server
 before_install:
-  - sh .travis/install_riakcs.sh
   - gem install bundler
 before_script:
   - cp config.yml.example config.yml
@@ -22,6 +21,3 @@ notifications:
       - http://hook-juggler.herokuapp.com/hooks/travis
     on_success: always
     on_failure: always
-# Force legacy Blue Box build for now
-sudo: required
-group: legacy