[Pkg-matrix-maintainers] Bug#960028: Build with babel version 7 to remove build dependency on node-babel-plugin-transform-async-to-bluebird

[Xavier]

Hi,

I fixed this bug by error (I didn't see that it was not under Pkg-JS
umbrella). I reproduced upstream build except:
 * browser build with webpack and a little hook to import global
   "buffer" from nodejs
 * node module build with a hook to fix babel work:

    perl -i -pe 's/=\s*import\(/= require\(/' lib/matrix.js

Sorry for this.

My work is available here (same error):
 https://salsa.debian.org/js-team/node-matrix-js-sdk

Cheers,
Xavier