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) {
  AtomPermissionManager::RequestHandler handler;
  if (!(val->IsNull() || mate::ConvertFromV8(args->isolate(), val, &handler))) {
    args->ThrowError("Must pass null or function");
    return;
  }
  auto permission_manager = static_cast<AtomPermissionManager*>(
      browser_context()->GetPermissionManager());
  permission_manager->SetPermissionRequestHandler(handler);
}
void Session::ClearHostResolverCache(mate::Arguments* args) {
  base::Closure callback;
  args->GetNext(&callback);
  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
      base::Bind(&ClearHostResolverCacheInIO,
                 make_scoped_refptr(browser_context_->GetRequestContext()),
                 callback));
}
void Session::AllowNTLMCredentialsForDomains(const std::string& domains) {
  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
      base::Bind(&AllowNTLMCredentialsForDomainsInIO,
                 make_scoped_refptr(browser_context_->GetRequestContext()),
                 domains));
}
void Session::SetUserAgent(const std::string& user_agent,