[Pkg-javascript-devel] Bug#941700: Bug#941700: Bug#941700: Update babel to version 7

[Evgeny Kapun]

> [14:53:55] ReferenceError: [BABEL]
> /home/pravi/forge/debian/git/js-team/node-babel/packages/babel-parser/src/x.js:
> Unknown option: base.envName. Check out
> <http://babeljs.io/docs/usage/options/> for more information about options.

The reason for this error and other errors is that this version uses multiple Babel features introduced in Babel 7, such as:
* envName option [1]
* babel.config.js file [2]
* Numeric separator [3]

For these reasons, it doesn't seem possible to build Babel 7.4.5 using Babel 6. I see two possible ways to solve this:
1. Bootstrap Babel manually, that is, build it locally using Babel installed from NPM and upload the resulting binary packages.
2. First package an older version of Babel, such as 7.0.0, then use it to build the current version.

Some other notes:
* The version being packaged is 7.4.5, but the latest stable version is already 7.6.0.
* During build, it is better to set NODE_ENV=production, because otherwise it will build for the current version of Node, so the resulting code may not run on older versions. With NODE_ENV=production, it will build for Node 6.9 and later (this is specified in babel.config.js).

[1]: https://babeljs.io/docs/en/options#envname
[2]: https://babeljs.io/docs/en/config-files#root-babelconfigjs-files
[3]: https://babeljs.io/docs/en/babel-plugin-proposal-numeric-separator