Remove CLI related files. Fixes #117

This goes together with https://github.com/wsdl2phpgenerator/wsdl2phpgenerator-cli/pull/1
As I see it we still need `symfony/options-resolver` as a dependency. It is used by [the `Config` class](https://github.com/wsdl2phpgenerator/wsdl2phpgenerator/blob/3.x/src/Wsdl2PhpGenerator/Config.php#L25),