Class mod ratelimit added

[Pawa2NR]

Summary

Added class defination for enabling mod_ratelimit

Additional Context

Add any additional context about the problem here.

• Root cause and the steps to reproduce. (If applicable)
• Thought process behind the implementation.

Related Issues (if any)

Mention any related issues or pull requests.

Checklist

• 🟢 Spec tests.
• 🟢 Acceptance tests.
• Manually verified. (For example puppet apply)

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[ekohl]

Could you add a basic test in spec/classes/mod? It's probably trivial, but it's good to very things work.

An acceptance test in spec/acceptance would be even more valuable.