Limit spam capabilities

[Sammers21]

Zerocrat is good at turning an issue/pull request into a completely messed up place. Here is the example: https://github.com/jcabi/jcabi-http/pull/180, and the messages are really annoying and makes people angry.

I would suggest limiting zerocract capabilities to spam in the following way: keep only one message per issue/pull request and update it to the actual state when needed. The idea is to either to delete the old message or keep the old one and update it constantly

[0crat]

@g4s8/z please, pay attention to this issue

[0crat]

@sammers21/z this project will fix the problem faster if you donate a few dollars to it; just click here and pay via Stripe, it's very fast, convenient and appreciated; thanks a lot!

[Sammers21]

@Sammers21/z this project will fix the problem faster if you donate a few dollars to it; just click here and pay via Stripe, it's very fast, convenient and appreciated; thanks a lot!

@0crat, No I would not donate any dollars.

[0crat]

Are you speaking to me or about me here; you must always start your message with my name if you want to address it to me, see §1