Discuss moving middleware to routing library

[davidbyoung]

Currently, middleware is in the Http library. However, it seems to be more of a routing component. The routing library currently relies on the Http library because Opulence disagrees with PSR7's implementation. If Opulence ever moves to a standard request/response library, the only library that should be affected is the routing library. So, I am proposing moving middleware from the Http library to the routing library. A bonus would be that the only dependency the routing library would have is the closure serialization library.

What does everyone think?