Upgrade deprecated npm packages

[szyn]

When installing packages with npm, I get the following warnings:

npm WARN deprecated node-uuid@1.4.8: Use uuid module instead
npm WARN deprecated babel-preset-es2015@6.24.1: 🙌  Thanks for using Babel: we recommend using babel-preset-env now: please read babeljs.io/env to update!

It's just a warning, but I think it's a good idea to upgrade the packages!
If you don't mind, I'll make changes that and create pull requests.

[hiroyuki-sato]

@szyn JFYI. #797 has been created. It update babel-preset-es2015.

• node-uuid (UI: Upgrade node-uuid to uuid #744)
• babel-preset-es2015: (Update Node.js 8.x for digdag-ui and introduce NPM package locks #797)

[muga]

@szyn @hiroyuki-sato sorry, I was not aware of this ticket. We started working on upgrading Node.js v8.x #797. Please take a look and let me know if you have any concerns/suggestions.

[muga]

I will merge #797 into master and include it in next version. Please take a look and feel free to comment anywhere when you get a chance.

[hiroyuki-sato]

@muga I succeed build dda03af (merged #797) in my enviromnet. Thank you!

[muga]

@hiroyuki-sato thank you for testing. It looks like other warnings are still there though:-)