Merge pull request #618 from fmarier/useless_requires

Remove unnecessary requires
Upgrade picoModal to 2.0.1

This is the latest upstream version, available at this URL:

  https://github.com/Nycto/PicoModal/releases/tag/2.0.1
Switch to the non-minified version of picoModal to ease debugging

The addon will be gzipped anyways, so the size difference should
not matter too much (3.4k v. 1.4k).
Upgrade D3 to 3.4.13

UThis is the latest upstream version, available at this URL:

  https://github.com/mbostock/d3/releases/tag/v3.4.13
Switch to a non-minified version of D3 to ease debugging

The addon will be gzipped anyways, so the size difference should
not matter too much (71k v. 51k).