.travis.yml in multiverse-0.1.2 vs .travis.yml in multiverse-0.2.0

@@ -1,14 +1,19 @@
 language: ruby
 rvm: 2.4.2
 gemfile:
   - Gemfile
 sudo: false
-before_install: gem install bundler
+before_install:
+  - gem install bundler
+  - unset RAILS_ENV
+  - unset RACK_ENV
 script: bundle exec rake test
 notifications:
   email:
     on_success: never
     on_failure: change
 env:
-  - RAILS_VERSION=5.1.4 RAILS_ENV=development
-  - RAILS_VERSION=5.0.6 RAILS_ENV=development
+  - RAILS_VERSION=5.2.0.rc1
+  - RAILS_VERSION=5.1.4
+  - RAILS_VERSION=5.0.6
+  - RAILS_VERSION=4.2.10