Bump version 2.7.1 

Bump version 2.7.0 

Bump version to 2.6.0 

move license files and bump to versoin 2.5.0 

fix build status badge 

update changelog 

bump version to 1.8.3 

bump version to 2.3.1 to fix #93 

bump version to 2.3.0 

bump version to 2.2.1