Proposal: drop support for PHP 5.6 and move to at least 7.2

[madman-81]

Since PHP support for 5.6 has stopped long ago and even version 7.1 only has security support (until December 1st), I would like to propose to set the required PHP version to >=7.2. This would, allow for some clean up of code, enable more type hinting, etc.

Please let me know if other people would like move forward too or if there are any reasons why not to do this.

[madman-81]

@Torann Would be nice to have your input on this. If you agree, I could also add a pull request for this if you like to.

[Torann]

Sounds great to me

[madman-81]

Great, I'll start working on that soon then! Since this could result in quite some changes, it would be convenient if the other pull requests are reviewed and merged before starting on this one. This makes things a bit easier with less merge conflicts. Could you have a look at them?

[Torann]

I'll look into doing this for the next release and make it the official v1.0 release

[Torann]

Just started 1.0.0 🎆