Release v0.21.0 with hyper 1.0 and friends
Release v0.20.0
Release v0.20.0-rc.7
Release v0.20.0-rc.6
Release v0.20.0-rc.5
Release v0.20.0-rc.4
Release v0.20.0-rc.3
Release v0.20.0-rc.2
Release v0.20.0-rc.1
Release v0.19.3