Upgrade iRedMail 0.7.4 > 0.8.5

======== Required information ====
- iRedMail version: 0.7.4
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: Centos 6.4
- Related log if you're reporting an issue:
====
HI! I have one server Centos 6.4 with iRedMail 0.7.4.
I would like to update the version of iRedMail to 0.8.5.
There is an automatic procedure?

Thanks

Daniele
Florence, Italy.