replace deprecated Buffer

[Bernhard Weichel]

Request

get rid of

node:7190) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.

solution approach

the issue stems from node module encoding see (andris9/encoding#21). Either we get a fix from there or we remove encoding ...