Implement plugin feature, resolve #9
Update README
Improve plugin structure
Update README
Add googkit test
Add test for lib.clone
Add how-to-test
Add a test for lib.download
Update googkit test
Support python3
python3 support
python3 support
fix to a bug on python3
Refix a bug on python3
Fix duplicated ns "commands"
Fix a test bug
Add a test for lib.config
Add a test for lib.environment
Add a test for lib.unzip
Uodate a test for lib.config