Release 0.8.1

Release 0.8.0

Release 0.7.1

version 0.7.0

https://github.com/egraphs-good/egg/blob/main/CHANGELOG.md#070---2021-11-23

(cargo-release) egg version 0.6.0

(cargo-release) egg version 0.5.0

(cargo-release) egg version 0.4.1

(cargo-release) egg version 0.4.0

(cargo-release) egg version 0.3.0

(cargo-release) egg version 0.2.0