[release] v8.0.0

[niftylettuce]

• [ ] Install and document installation for Pyzor SpamAssassin plugin https://spamassassin.apache.org/full/3.3.x/doc/Mail_SpamAssassin_Plugin_Pyzor.html (ref: https://forums.zimbra.org/viewtopic.php?t=65628#p288618)
• [ ] Install and document installation for Razor2 SpamAssassin plugin https://spamassassin.apache.org/full/3.2.x/doc/Mail_SpamAssassin_Plugin_Razor2.html (ref: https://forums.zimbra.org/viewtopic.php?t=65628#p288618)
• Add Spamhaus, SpamCop, Barracuda, Lashback, PSBL (added in v3.1.0)
• Allow users to forward to disposable email addresses (added in v3.1.0)
• Status page with DNSBL check, avg response time, deliverability tests (Gmail/Apple/Outlook/Yahoo/ProtonMail)
• Dec 1 2020 Reminder (certbot renewal + lsync setup)
• Remove old server
• Encrypted TXT record
• Disposable email addresses (at your domain or forwardemail.net with mail relay using X-Relay-Hash?) + extension
• Drop bluebird
• Note about setting PTR records
• Cannot read property 'address' of undefined on empty MAIL FROM <>
• Demo video