Try removing bundler from Gemfile to fix TravisCI tests on JRuby
Try removing bundler from Gemfile to fix TravisCI tests on JRuby

My thinking is that whatever version is installed by the system
should be sufficient. However, commit e5cb335b44d4d6d710ffc0070c90a087879f61d4
apparently came to a different conclusion, so testing to find out.

The build error was:

  Bundler could not find compatible versions for gem "bundler":
    In Gemfile:
      bundler (= 1.11.2)
      bundler (= 1.11.2) java
    Current Bundler version:
      bundler (1.12.5)
  This Gemfile requires a different version of Bundler.
  Perhaps you need to update Bundler by running `gem install bundler`?
  Could not find gem 'bundler (= 1.11.2)' in any of the sources

objects-on-rails/display-case,objects-on-rails/display-case,pdobb/display-case,pdobb/display-case