This also includes a dependnecy on a polyfill targeting older Node.js versions where Buffer.alloc() and Buffer.from() API is not implemented (Node.js < 4.5.0 and some 5.x versions).

This is mostly a line-to-line change, though in some cases, minor code simplification was done, e.g.

var version = new Buffer(1);
version.writeUInt8(1, 0);

was transformed into

var version = Buffer.from([1]);

Ref: nodejs/node#19079
Ref: https://nodejs.org/api/deprecations.html#deprecations_dep0005_buffer_constructor
Ref: https://nodejs.org/api/buffer.html#buffer_class_buffer
Ref: https://github.com/ChALkeR/safer-buffer/blob/master/Porting-Buffer.md
Fixes: #45

Note that this does not completely solve the problem yet, for a complete solution, asn1 (a dependency) should also receive this fix (see below for that one).

But fixing the API usage in this package is still required, and a significant portion of tests pass without ever hitting the deprecated Buffer API in asn1 dependency.