Add check for calls to remote_byebug to Lint/Debugger Cop.

[riley-klingler]

The byebug gem added a method called remote_byebug for triggering breakpoints in ruby code running remotely. This PR makes the Debugger cop fail if it finds a call to remote_byebug.

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Before submitting the PR make sure the following are checked:

• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists). (N/A)
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Run bundle exec rake default. It executes all tests and RuboCop for itself, and generates the documentation.

[koic]

Thanks!