Add `roave/you-are-using-it-wrong` dependency

[Ocramius]

Note: this will require a major version bump, because it will effectively lead to failed installations (rather than composer update sticking to previous versions).

See https://github.com/Roave/you-are-using-it-wrong

• Requires #463: psalm-specific type declarations for generic/intersection types of proxies #465
• Requires Provide @psalm-param class-string<T> documentation for proxy factories and anything type-hinted object and : object #463