Plack::Middleware::NoMultipleSlashes removes all multiple slashes from your
PATH_INFO.

Multiple slashes in requests are a common problem, which many share. Apparently,
the RFC states that you should be able to expect different results from
http://server/ and http://server// (notice the second slash), so if the
frameworks wish to maintain RFC compatibility, they cannot remove those extra
slashes for you.

While you can handle this issue in a reverse proxy, in a rewrite module or in
your code, I find it more comfortable to have Plack take care of it in the thin
layer called Middlewares.

By enabling this middleware, all multiple slashes in your requests will
automatically be cut. //hello///world becomes /hello/world. Simple as that.