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
mate::Arguments* args) {
  browser_context_->SetUserAgent(user_agent);
  std::string accept_lang = l10n_util::GetApplicationLocale("");
  args->GetNext(&accept_lang);
  auto getter = browser_context_->GetRequestContext();
  getter->GetNetworkTaskRunner()->PostTask(
      FROM_HERE,
      base::Bind(&SetUserAgentInIO, getter, accept_lang, user_agent));
}
std::string Session::GetUserAgent() {
  return browser_context_->GetUserAgent();
}
void Session::GetBlobData(
    const std::string& uuid,
    const AtomBlobReader::CompletionCallback& callback) {
  if (callback.is_null())
    return;
  AtomBlobReader* blob_reader =
      browser_context()->GetBlobReader();
  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
      base::Bind(&AtomBlobReader::StartReading,
                 base::Unretained(blob_reader),
                 uuid,
                 callback));
}
void Session::CreateInterruptedDownload(const mate::Dictionary& options) {