tongdaitructuyen/System requi - Mautic V3

## System requi - Mautic V3
System is compatible with the upgrade. The checks are:

* PHP version must be 7.2 or 7.3
* MySQL version needs to be >= 5.7.14 or MariaDB >= 10.1
* Is custom  `api_rate_limiter_cache`  set? TODO add docs
* Is Mautic's root directory writable?
* Are there items in the  `spool/default`  folder? This indicates that there are still emails in the queue
* Is the free disk space at least 2x the current Mautic 2 installation?
* Do you at least have Mautic 2.16.3 installed?
* Is PHP's  `max_execution_time`  either 0 (unlimited) or > 240? If not, we try to set it, if that doesn't work, we show an error
* Is  `mysqldump`  available for creating database backups?
* Is there a Mautic 3 upgrade package available for download?
* Is the upgrade "kill switch" activated? (Mautic's Product Team can enable a Kill Switch which will show a warning to users that there might be problems with the upgrade. Read more HERE (TODO))
* Are there any custom plugins installed? If yes, we show a warning that users should check if those plugins are compatible with Mautic 3 or temporarily disable them
* Get the amount of available database migrations. If that fails, we show a warning
* Check if the platform is Windows. If it is, we show a warning that cache creation is significantly slower on this platform and that the user should be extra patient.
* Is PHP's  `memory_limit`  equal to or higher than 256M? If not, we try to set it, if that doesn't work, we show an error
	System is compatible with the upgrade. The checks are:

	* PHP version must be 7.2 or 7.3
	* MySQL version needs to be >= 5.7.14 or MariaDB >= 10.1
	* Is custom `api_rate_limiter_cache` set? TODO add docs
	* Is Mautic's root directory writable?
	* Are there items in the `spool/default` folder? This indicates that there are still emails in the queue
	* Is the free disk space at least 2x the current Mautic 2 installation?
	* Do you at least have Mautic 2.16.3 installed?
	* Is PHP's `max_execution_time` either 0 (unlimited) or > 240? If not, we try to set it, if that doesn't work, we show an error
	* Is `mysqldump` available for creating database backups?
	* Is there a Mautic 3 upgrade package available for download?
	* Is the upgrade "kill switch" activated? (Mautic's Product Team can enable a Kill Switch which will show a warning to users that there might be problems with the upgrade. Read more HERE (TODO))
	* Are there any custom plugins installed? If yes, we show a warning that users should check if those plugins are compatible with Mautic 3 or temporarily disable them
	* Get the amount of available database migrations. If that fails, we show a warning
	* Check if the platform is Windows. If it is, we show a warning that cache creation is significantly slower on this platform and that the user should be extra patient.
	* Is PHP's `memory_limit` equal to or higher than 256M? If not, we try to set it, if that doesn't work, we show an error