v1.20200108

• NEW FEATURE: Postgres support #150
• removed dist::zilla
• additional tests enabled
• html UI: use https URLS everywhere
• SPF: don't warn when scope is missing from reports
• receive: permit other MIME types that have xml.gz filename
• DKIM: when message has no result, add "none"
• sqlite: add default current_timestamp
• bin/install_deps.pl: apt improvements