Response caching middleware doesn't allow injection of IResponseCache

The response caching middleware uses a MemoryCache object to cache responses and it is hardcoded in the public constructor to use it. See: https://github.com/aspnet/ResponseCaching/blob/master/src/Microsoft.AspNetCore.ResponseCaching/ResponseCachingMiddleware.cs. This makes it impossible to provide your own implementation of IResponseCache. I would for example like to create a DistributedResponseCache so I can have better horizontal scaling.