I think it works. I do get 2 failures, but I don't think they're related:

```
Failures:

  1) No runner should not run the spec command
     Failure/Error: vim.command 'RunCurrentFile'
     Vimrunner::InvalidCommandError:
       Vim(call):E117: Unknown function: <SNR>21_throw
     # ./spec/no_runner_spec.rb:22:in `run_command_in_unknown_file'
     # ./spec/no_runner_spec.rb:9:in `block (2 levels) in <top (required)>'

  2) No runner should alert the user that it could not run the command
     Failure/Error: vim.command 'RunCurrentFile'
     Vimrunner::InvalidCommandError:
       Vim(call):E117: Unknown function: <SNR>21_throw
     # ./spec/no_runner_spec.rb:22:in `run_command_in_unknown_file'
     # ./spec/no_runner_spec.rb:15:in `block (2 levels) in <top (required)>'
```