coding standard
Files can have defined minimal php version for linting

If the system's PHP version doesn't match the rule then the file is skipped.
The rule must be on the first line in the file, right after the opening php tag

```php
<?php // lint >= 5.4
```
Require jakub-onderka/php-console-highlighter for development and CI builds
Fixed coloring of linting result
Fixed repeated calling of Process::isFinished()
Run tests in parallel