Bump version to 0.6.0 (open-mmlab#996)

* initial

* update changelog

* update version num

* fix

* fix letter case

* grammar

Bump version to 0.5.0 (open-mmlab#904)

Bump version to 0.4.1 (open-mmlab#755)

* 0.4.1 change log

* update version number

* update changelog

* update changelog

* update dates

* update version

Bump version to 0.4.0 (open-mmlab#672)

Bump version to 0.3.0 (open-mmlab#461)

* Bump version to 0.3.0

* update changelog

Bump version to 0.2.1 (open-mmlab#378)

update publish yml (open-mmlab#218)

add unit test for textsnake (open-mmlab#61)