Remove usages of deprecated Buffer()

[connorjclark]

(node:5321) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.

The above deprecation error is logged from new version of Node when using this package.

[Wonder233]

I have the same problem 😒

[PavelPivkin]

Are there any problems with merging it? @dcodeIO https://github.com/protobufjs/bytebuffer.js/pull/103