Pre-release of 1.0.0

1.0.0 release will contain following facilities:

• SSL-enabled Postfix/Dovecot.
• SpamAssassin with auto-learning at a per-user base.
• Certbot and auto-renewal.
• Easy-to-use PostfixAdmin.
• Modern webmail system RainLoop.
• Securing web ui with HTTPS/HTTP2.