v1.13.0

Feature

• Add optional SpamAssassin integration to display "spamminess" scores (#233)
• Add option to disable SMTP reverse DNS (rDNS) lookup (#230)
• Display List-Unsubscribe & List-Unsubscribe-Post header info with syntax validation (#236)

Fix

• Display multiple whitespace characters in message subject & recipient names (#238)
• Sendmail support for -f 'Name <email[@example](https://github.com/example).com>' format

Chore

• Compress compiled assets with npm run build
• Update Go modules
• Update node modules