Changes from gocardless/gocardless-pro-ruby-template

[gocardless-ci-robot[bot]]

This pull request was automatically created from the gocardless/gocardless-pro-ruby-template repository by the push-files action (workflow run).

[jamiecobbett]

~The removal of .gitignore, .rspec, .rubocop.yml and .travis.yml are expected because we're now removing files that aren't included in the generated template.~

~None of these seem to be causing a problem - I can still install deps locally, run specs etc. Gemfile.lock does now appear in git status because .gitignore is not excluding it.~

This has been resolved by https://github.com/gocardless/gocardless-pro-ruby-template/pull/577