PHP 8.0 compatibility

Now the PHP minimum is 7.2, but it's compatible with PHP 8.0.

2.0.0

Make WPML plugins compatible to PHP 7.4

https://onthegosystems.myjetbrains.com/youtrack/issue/wpmlga-560

1.2.8

Make OTGS_TestCase compatible with tests modified for phpunit-7.

https://onthegosystems.myjetbrains.com/youtrack/issue/wpmlga-560

1.2.7

Add handling protected properties and methods to OTGS_TestCase.