Revert "Fiddle with msgpack bytes vs unicode"
Revert "Fiddle with msgpack bytes vs unicode"

This reverts commit 73ad21db33b573e5f698e1eecf1b947b24bec450.

explosion/thinc,explosion/thinc,explosion/thinc,spacy-io/thinc,spacy-io/thinc,explosion/thinc,spacy-io/thinc