v1.1.0

Spamassassin:

• Don't restart Spamassassin when no updates were installed
• Integrated Pyzor and Razor2

MTA:

• Greylisting can be enabled optionally

Web:

• The container runs in read_only mode
• Improved image size by switching to alpine linux
• Improved performance by switching to php-fpm + nginx instead of Apache2

Other:

• Improved travis-ci integration
• Updated README