Improvements 🔧

Added TeamCity error formatter (#295), thanks @MaximilianKresse!
Updated nikic/php-parser to 4.8.0 (https://github.com/phpstan/phpstan-src/commit/65a74c660d09141b6d69439f99e01a922e0409ab)
Updated LexerFactory to take advantage of the new Emulative lexer capabilities (https://github.com/phpstan/phpstan-src/commit/71013bc41eec44b9a5796ec6dd8c84b5e01b847e) - some of the new syntax from PHP 7.3, 7.4, and 8.0 will now be marked as parse error on lower PHP versions

Bugfixes 🐛