Fix test mock recordings

LWP::Protocol::PSGI needs to be 0.04; otherwise, it only records the first of the request/response pairs, as discussed in #65. 

    cpanm MIYAGAWA/LWP-Protocol-PSGI-0.04.tar.gz

Also, once the recordings are made, I was running into issues where the stringified versions of the request/response pairs were out of order, but still equal. I found a way to check if they're deeply_equal using Storable::Freeze.

Does Storable need to be in the dist.ini? It's a core module, but some of the other reqs in there are also core modules.

If we're not interested in maintaining this way of testing the module, feel free to refuse this PR :)