Incremented nikic/PHP-Parser dependency from v0.9.x to v1.x

# Changes

* Increment [php-parser](https://github.com/nikic/PHP-Parser) dependency from `0.9.*` to `~1.0`

# Reasons

* Version `0.9.x` of [php-parser](https://github.com/nikic/PHP-Parser) is [no longer maintainer[(https://github.com/nikic/PHP-Parser#php-parser)
* Version `0.9.x` cannot handle newer [PHP 5.6 features](http://php.net/ChangeLog-5.php#5.6.0)
  * Example being [variadic function arguments](http://php.net/manual/en/functions.arguments.php#functions.variable-arg-list) which cause a lexer error with version `0.9.x`
* All PHPUnit tests pass with the change to version `1.0.1`