[Features] logs fetch errors / audit time estimation / slack / queue in kafka or redis

Hi @popstas ,

Hope you are all well ! And Happy New Year to all !

I had a play with site-audit-seo and figured out some things to add:

• Slack notification (I already started to implement that one) but something more pluggable would be nice (Slack,Jira,Email,...)
• Estimate the audit time if follow sitemap is enabled with an average time of 1s per page
• Create a queue of urls ro crawl in redis or kafka per audits if the server restart to resume tasks
• Log errors while a request failed, it can be helpful to identify failing url rewriting rules

And again, you did an amazing job with this project. Thanks again and again :-)

Thanks for any insights or inputs on that

Cheers,
Luc Michalski