Don't `require('buffer')`

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.

Start by tracing where http-browserify requires buffer and how the auth parameter is handled. Compare the stated options—documenting that auth is unsupported or using a base64 library—and inspect the existing dependency setup before choosing a direction. Done means the buffer dependency is no longer unnecessarily required and the auth behavior is explicit and covered by the project’s existing checks.

Written by the indexing model from the issue text.