simplify webpack setup

See merge request !24

Bump PS to 0.13.6

See merge request !25

(cherry picked from commit 2e05fc87)

* make webpack dev server work again
* use the purescript compiler output CommonJS modules from src/index.js
* add prebuild "yarn compile" script
* with "yarn dev", you now only need to run a purs ide plugin or run "yarn compile"

Merge branch 'dev-async-file-upload' of ssh://gitlab.iscpif.fr:20022/gargantext/purescript-gargantext into dev-async-file-upload

Also, html code element edits text properly (no state, just refs which
prevents cursor jumping).

Thanks!

This way the popup really floats, avoiding being caught up in absolute
divs with limited width etc.

Instead, add it to removed node ids and hide them via transformed graph
functionality.