This reverts commit 07bc29c494.
probably 3.12 works fine, but for technical reasons the automated
tests don't work yet. hoping once we drop 3.6 support then can get
the 3.12 tests working properly..
this has 100% test coverage and i intend to keep it that way. api
docs have a good start but still need narrative. several more things
must be added before i can seriously consider incorporating into
rattail but this seemed a good save point