Clean up npm deploy package / add reading from persisted artifacts

[RnkSngh]

npm package for deploy scripts is deployed here

there's support for deploying packages, either from javascript or from command line. And artifacts are saved to .json files and should include all files.

There still needs to be some clean up:

• add support for reading deployed contract files from persisted artifacts (instead of having to specify them in yaml)
• get contract verification working (lower priority)
• add docs (lower priority)