declare property in tests

added isurl() #2

Parser no longer needs an instance of LessC

Merge branch '0.6-dev' of github.com:MarcusSchwarz/lesserphp into 0.6…

…-dev

bump version to 0.5.5

updating HISTORY.md

PHP 7.4 support (MarcusSchwarz#16)

* Add PHP 7.4snapshot to travis CI

* Fix compatibility with PHP 7.4

Array and string offset access syntax with curly braces is deprecated
/home/travis/build/phy25/lesserphp/src/LesserPhp/Compiler.php:1793

Trying to access array offset on value of type bool
/home/travis/build/phy25/lesserphp/src/LesserPhp/Compiler.php:953

* Fix styleci warning

adding MarcusSchwarz#14 into current stable