Will be nice to clear auth credentials. For example, I'm using a proxy that accepts options via username:

```
proxy.com:8080
user: wiliam_country_US
```

So, if I want to change the peer node, I change my username:

```
proxy.com:8080
user: wiliam_country_GB
```

But, I'm not changing the proxy, so electron has valid credentials and is not going to trigger `login` event.

I'm searching the way to clean auth settings so electron asks them again.
atom/browser/api/atom_api_session.cc
int64_t offset = 0, length = 0;
  double start_time = 0.0;
  std::string mime_type, last_modified, etag;
  base::FilePath path;
  std::vector<GURL> url_chain;
  options.Get("path", &path);
  options.Get("urlChain", &url_chain);
  options.Get("mimeType", &mime_type);
  options.Get("offset", &offset);
  options.Get("length", &length);
  options.Get("lastModified", &last_modified);
  options.Get("eTag", &etag);
  options.Get("startTime", &start_time);
  if (path.empty() || url_chain.empty() || length == 0) {
    isolate()->ThrowException(v8::Exception::Error(mate::StringToV8(
        isolate(), "Must pass non-empty path, urlChain and length.")));
    return;
  }
  if (offset >= length) {
    isolate()->ThrowException(v8::Exception::Error(mate::StringToV8(
        isolate(), "Must pass an offset value less than length.")));
    return;
  }
  auto download_manager =
      content::BrowserContext::GetDownloadManager(browser_context());
  download_manager->GetDelegate()->GetNextId(base::Bind(
      &DownloadIdCallback, download_manager, path, url_chain, mime_type, offset,
      length, last_modified, etag, base::Time::FromDoubleT(start_time)));
}
v8::Local<v8::Value> Session::Cookies(v8::Isolate* isolate) {