create wt with a package JSON loaded remotely.

[dzeitman]

Would like to see --package <url-to-package.json> flag option added to the cli.

This would function similar to the wt create <url - to - js file> and point to the package.json file to enable required packages.

This would allow the creation of wt from remote files hosted on gist or other places.

[yavorg]

Repro:

• webtask code
• package.json

The following doesn't pick up the package.json:
wt create https://gist.githubusercontent.com/yavorg/42bd26ed5732759e1f6bf71258340084/raw/b9910d3df2496a957b677aa7fcd031405c1b83c6/forex.js