Gemfile.lockを消したら
$ bundle install
:
Could not find compatible versions
Because bundler-audit >= 0.6.1 depends on bundler >= 1.2.0, < 3
and the current Bundler version (4.0.0.dev) does not satisfy bundler >= 1.2.0, < 3,
bundler-audit >= 0.6.1 cannot be used.
:
ってプルリクチャーンス!!