Create postfix playbook
- Install and configure postfix.
- Add empty line.
- Change restart to reload.
- Add postmap, addresses, aliases and create folders.
- Install and configure postfix.
- Add empty line.
- Rename postfix-service to postfix-handlers.
- Use postfix reload instead of service reload feature.
- Move postfix to webservers.
- Add virtual_alias_maps to postfix playbook.
- Move all from common to web folder.

Fixes #6
Closes #33