* implement output.condition.details marshalling and remove signature field
* rename outputs[].condition.details.subfulfillments to subconditions
* simpler threshold depth overlow handling
* pass public_key as kwarg
* change ccv1 condition uri in docs
* import base58 at top in test_transaction
* tx version break step with server version
* fix regular expression for tx version
* restore docstring for Transaction version parameter
* add test for correct transaction version