The buffer implementation is a lot of code and http-browserify does not really need it to work. It is only needed for auth parameter to bas64 encode it.
Could it be document that the auth parameter is not supported or changed to depend on a base64 library or? Eg. base64-js which buffer-browserify depends on.
Where do you see require('buffer')? It looks like buffer is not directly required by http-browserify but rather by stream, which is needed to make the request and response objects be streams. Streams operate on Buffers, so it's required.
When I filled this was buffer directly required by http-browserify. Probably did someone resolve it and now, it has been reintroduced by stream.
This issue should be closed.