change v0.6.2 to v0.7.0 in changelog as well (#517)

* change v0.6.2 to v0.7.0 in changelog as well

* Update CHANGELOG.md

* Update CHANGELOG.md

---------

Co-authored-by: Nezar Abdennur <[email protected]>

Author: Yaoyx

CHANGELOG.md

@@ -1,8 +1,8 @@
 # Release notes
 
-## [Upcoming release](https://github.com/open2c/cooltools/compare/v0.6.2...HEAD)
+## [Upcoming release](https://github.com/open2c/cooltools/compare/v0.7.0...HEAD)
 
-## [v0.6.2](https://github.com/open2c/cooltools/compare/v0.6.1...v0.6.2)
+## [v0.7.0](https://github.com/open2c/cooltools/compare/v0.6.1...v0.7.0)
 
 ### New features
 * Add pool decorator to functions for supporting multiprocess