Auto DevOps code_quality check fails on Ruby 2.6
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### Summary
The `code_quality` check fails when using Ruby 2.6, as the Rubocop version being used does not support > Ruby 2.5.
This is an allowed failure so the Pipeline doesn't fail -- but it does remove a bit of the 'it just works' feeling.
We should upgrade Rubocop on whatever is running the `code_quality` check. Looks like anything > [0.60.0](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md#0600-2018-10-26) should work.
### Steps to reproduce
1. Create Ruby Project and upload to Gitlab
2. Enable Auto DevOps
3. Pipeline will run and code_quality check should fail.
### What is the current *bug* behavior?
Code quality check fails when using Ruby 2.6.
### What is the expected *correct* behavior?
Code quality check should execute when using Ruby 2.6.
### Relevant logs and/or screenshots

### Possible fixes
Upgrade to a newer version of Rubocop.
issue