Archiver 2.0.0

[ctalkington]

as the original and one of the major consumers of Archiver I wanted to reach out about changes coming over the next few days.

1. v2.0.0 will be released with support for node v4+ only; the main feature will be basic symlink support. additionally some modernization (promises etc) taking place in coming months.
2. v1.3.0 will only receive reasonable bug fixes (until 2017-12-31) and no new features. a separate branch has been created for these maintenance releases.

ref archiverjs/node-archiver#243

cc @XhmikosR

[XhmikosR]

Hey, @ctalkington.

v4 is required anyway since the Brotli patch so it shouldn't be an issue. That being said, if you could make any changes and provide a PR that would help.