Add ability to change version

Author: alexrudall

lib/ruby/openai/client.rb

@@ -1,15 +1,15 @@
 module OpenAI
   class Client
     include HTTParty
-    base_uri "https://api.openai.com/v1/engines"
+    base_uri "https://api.openai.com"
 
     def initialize(access_token: nil)
       @access_token = access_token || ENV["OPENAI_ACCESS_TOKEN"]
     end
 
-    def call(engine:, prompt:, max_tokens:)
+    def call(engine:, prompt:, max_tokens:, version: "v1")
       self.class.post(
-        "/#{engine}/completions",
+        "/#{version}/engines/#{engine}/completions",
         headers: {
           "Content-Type" => "application/json",
           "Authorization" => "Bearer #{@access_token}"