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/net/atom_url_request.h
void DoRemoveExtraHeader(const std::string& name) const;
  void DoSetAuth(const base::string16& username,
                 const base::string16& password) const;
  void DoCancelAuth() const;
  void DoCancelWithError(const std::string& error, bool isRequestError);
  void ReadResponse();
  bool CopyAndPostBuffer(int bytes_read);
  void InformDelegateAuthenticationRequired(
      scoped_refptr<net::AuthChallengeInfo> auth_info) const;
  void InformDelegateResponseStarted(
      scoped_refptr<net::HttpResponseHeaders>) const;
  void InformDelegateResponseData(
      scoped_refptr<net::IOBufferWithSize> data) const;
  void InformDelegateResponseCompleted() const;
  void InformDelegateErrorOccured(const std::string& error,
                                  bool isRequestError) const;
  api::URLRequest* delegate_;
  std::unique_ptr<net::URLRequest> request_;
  scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
  bool is_chunked_upload_;
  std::unique_ptr<net::ChunkedUploadDataStream> chunked_stream_;
  std::unique_ptr<net::ChunkedUploadDataStream::Writer> chunked_stream_writer_;
  std::vector<std::unique_ptr<net::UploadElementReader>>
      upload_element_readers_;
  scoped_refptr<net::IOBuffer> response_read_buffer_;
  DISALLOW_COPY_AND_ASSIGN(AtomURLRequest);
};
}  
#endif