Updater / Backup script

[fkosmala]

SuperHive doesn't need to save the on-chain data but need to have backup system for settings, theme and off-chain data.

Also, users need an easy updater to keep their SuperHivei nstance up to date.

Don’t know how I’ll do that but here’s some resources:

• GitHub API to retrieve latest version : https://api.github.com/repos/fkosmala/superhive/releases/latest
• PHP updater script from Travis Pessetto : https://github.com/travispessetto/script-updater-for-php
• PHP Backup Sentry package : https://github.com/iSemary/backup-sentry