Acceptance tests fail when running under JRuby

[nickcharlton]

881  Failures:
882
883  1) Bundle with custom path installs gems in the --path directory
884     Failure/Error:
885       raise RuntimeError, <<-error_message.strip_heredoc
886         Command #{command.inspect} exited with status #{exitstatus}. Output:
887         #{output.gsub(/^/, '  ')}
888       error_message
889     
890     RuntimeError:
891       Command "bundle exec appraisal install" exited with status 1. Output:
892         >> bundle check --gemfile='/home/travis/build/thoughtbot/appraisal/tmp/stage/gemfiles/rack.gemfile' || bundle install --gemfile='/home/travis/build/thoughtbot/appraisal/tmp/stage/gemfiles/rack.gemfile' --retry 1
893     Shared Example Group: :gemfile_dependencies_are_satisfied called from ./spec/acceptance/bundle_with_custom_path_spec.rb:38
894     # ./spec/support/acceptance_test_helpers.rb:162:in `block in run'
895     # ./spec/support/acceptance_test_helpers.rb:154:in `block in run'
896     # ./spec/support/acceptance_test_helpers.rb:149:in `in_test_directory'
897     # ./spec/support/acceptance_test_helpers.rb:153:in `run'
898     # ./spec/acceptance/bundle_with_custom_path_spec.rb:23:in `block in <main>'
899
900  2) Bundle with custom path when already installed in vendor/another installs gems in the --path directory
901     Failure/Error:
902       raise RuntimeError, <<-error_message.strip_heredoc
903         Command #{command.inspect} exited with status #{exitstatus}. Output:
904         #{output.gsub(/^/, '  ')}
905       error_message
906     
907     RuntimeError:
908       Command "bundle exec appraisal install" exited with status 1. Output:
909         >> bundle check --gemfile='/home/travis/build/thoughtbot/appraisal/tmp/stage/gemfiles/rack.gemfile' || bundle install --gemfile='/home/travis/build/thoughtbot/appraisal/tmp/stage/gemfiles/rack.gemfile' --retry 1
910     Shared Example Group: :gemfile_dependencies_are_satisfied called from ./spec/acceptance/bundle_with_custom_path_spec.rb:51
911     # ./spec/support/acceptance_test_helpers.rb:162:in `block in run'
912     # ./spec/support/acceptance_test_helpers.rb:154:in `block in run'
913     # ./spec/support/acceptance_test_helpers.rb:149:in `in_test_directory'
914     # ./spec/support/acceptance_test_helpers.rb:153:in `run'
915     # ./spec/acceptance/bundle_with_custom_path_spec.rb:23:in `block in <main>'
916
917. Finished in 22 minutes 23 seconds (files took 1.1 seconds to load)
918. 88 examples, 2 failures