Do not use Buffer.isBuffer - to allow cross context usage

[gpetrov]

The bynode buffer is been checked first for valid buffer before evaluation, but if fails if the buffer is from other context because the node implementation is very strict. See https://stackoverflow.com/questions/44216449/why-isbuffer-returns-false-for-an-fs-readfilesync-call-without-encoding

So just replace it with, more easy direct isBuffer function like

https://github.com/feross/is-buffer/blob/master/index.js

[OsamaAbbas]

Good idea, thanks for the suggestion.

[gpetrov]

Any news on this?

[OsamaAbbas]

Any news on this?

Honestly, I forgot about this suggestion. I will add it in the next version, hopefully soon.