Added ability to pass http client request options like the timeout

[wkok]

Closes #44

Sample usage:

(api/create-chat-completion {:model "gpt-3.5-turbo"
                             :messages [{:role "system" :content "You are a helpful assistant."}
                                        {:role "user" :content "Who won the world series in 2020?"}
                                        {:role "assistant" :content "The Los Angeles Dodgers won the World Series in 2020."}
                                        {:role "user" :content "Where was it played?"}]}

                            {:request {:timeout 60000}})    ;; <== This