v1.6.2 and v1.7.4 to history

tweak history

tweak history

prepare for v1.8.1

update license for 2021

tempoarily pin pip

prepare for v1.7.2 release

correct history

build history and uprev version (pydantic#2040)

* build history and uprev version

* tweak history

* add pydantic#744 to changelog

* bump

uprev