bump opencv_core and opencv_dart to 1.4.1

fix test

Merge pull request #296 from rainyl/v1.3.3

update changelog, readme, bump to v1.3.3

bump version to 1.3.2

fix publish

update changelog

Merge pull request #274 from rainyl/docs

more tests, bump opencv_core and opencv_dart to 1.3.0

bump version to v1.2.5

Merge pull request #237 from rainyl/1.2.4

bump version to v1.2.4

Merge pull request #229 from rainyl/1.x-vec-fix

1.x vec fix