rails: 'check_version_conflict': using 'rails new', with a version, when Rails 5.1.X installed

Steps to reproduce

Make sure Rails 5.0.3 is installed on the system. Uninstall Rails 5.1.0 and Rails 5.1.1 (along with all of their component gems). Run

rails _5.0.3_ new foo --skip-bundle

Everything works fine. Now install Rails 5.1.1. Run the same command

rails _5.0.3_ new foo --skip-bundle

Expected behavior

rails new should be to create a Rails 5.0.3 application.

Actual behavior

rails new crashes with the following error in the console

…/.rvm/rubies/ruby-2.3.4/lib/ruby/site_ruby/2.3.0/rubygems/specification.rb:2278:in `check_version_conflict’: can’t activate activesupport-5.1.1, already activated activesupport-5.0.3 (Gem::LoadError)

System configuration

Rails version: See above

Ruby version: Tested with Ruby 2.3.4 and 2.3.3.