Support JSON formatting for RuboCop
At the moment, the only format that's supported by CircleCI is the JUnit format for RuboCop.
The problem with this, is that the custom formatter for this has been abandoned and the only alternative to be used right now is `pronto`, which requires a lot more setup for simply running RuboCop.
By default, RuboCop has a JSON output very similar to Cucumber, but the CircleCI CLI doesn't seem to recognise the output from RuboCop:
Found no test results, skipping