Update version and CHANGES for 2.7

Update version and CHANGES for 2.7

Update version and CHANGES for 2.7

update ci to run on 2_x_dev branch

update ci to run on 2_x_dev branch

create 2.5.0 release

create 2.5.0 release

2.4.2 release

2.4.2 release

2.4.1 release