Update README for clear development goal

Add scaffold example
100% coverage for get-config
100% coverage for get-keys
100% coverage get-docker
Promisify container instance
Fix logic errors in mark-tar module
Update bind-arg location
Improve make-tar module
100% cover get-images
100% cover get-containers
Tested CLI
Set default at ssd bin, instead of get-config
Refactor handle build response
Improve testing
100% cover get-image
Fix cleanup container not remove container bug

100% cover
100% cover start-container
100% cover up.js
Merge pull request #3 from daiweilu/refactor

Refactor