Pull across changes from rspec/rspec-rails#1982

Author: JonRowe

travis/.travis.yml

@@ -6,11 +6,9 @@ cache:
     - ../bundle
 before_install:
   - gem update --system # https://github.com/travis-ci/travis-ci/issues/8978#issuecomment-354036443
+  - gem install bundler
   - unset _JAVA_OPTIONS
   - "script/clone_all_rspec_repos"
-  # Note this doesn't work on JRUBY 2.0.0 mode so we don't do it, the excluded versions are broken on Ruby 2.3
-  - if [ "jruby" != "$TRAVIS_RUBY_VERSION"  ]; then gem install bundler --version "1.11.2"; fi
-  - alias bundle="bundle _1.11.2_"
 bundler_args: "--binstubs --standalone --without documentation --path ../bundle"
 script: "script/run_build"
 rvm: