nette 3.1 compatibility

[vrestihnat]

Simple adjustments for nette 3.1 and latte 2.10.1 compatibility. Please publish changes.

[janbarasek]

Hi, can I also request a tag release? This makes it impossible to upgrade projects. Thanks!

[martincarda]

Hi, can I also request a tag release? Thanks!

[namo-R]

@enumag please ;)

[enumag]

Hmm... maybe we should add PHP 8.0 into travis first? Just to be sure it works there.

[ViPErCZ]

It is set release date?

[ViPErCZ]

It definitely works on PHP 7.2 with Nette 3.1 ;-)