Update example model in README.md (#66)

* Update example model in README.md

gpt-4o-mini is now, according to OpenAI, faster smarter and cheaper than gpt-3-turbo

* Update everywhere

* fixup

Author: LilithHafner

README.md

@@ -28,7 +28,7 @@ __⚠️ We strongly suggest setting up your API key as an ENV variable__.
 
 ```julia
 secret_key = ENV["OPENAI_API_KEY"]
-model = "gpt-3.5-turbo"
+model = "gpt-4o-mini"
 prompt =  "Say \"this is a test\""
 
 r = create_chat(
@@ -57,7 +57,7 @@ provider = OpenAI.OpenAIProvider(
 )
 response = create_chat(
     provider,
-    "gpt-3.5-turbo",
+    "gpt-4o-mini",
     [Dict("role" => "user", "content" => "Write some ancient Greek poetry")]
 )
 ```

src/OpenAI.jl

@@ -312,7 +312,7 @@ For more details about the endpoint and additional arguments, visit <https://pla
 ## Example:
 
 ```julia
-julia> CC = create_chat("..........", "gpt-3.5-turbo", 
+julia> CC = create_chat("..........", "gpt-4o-mini", 
     [Dict("role" => "user", "content"=> "What is the OpenAI mission?")]
 );
 
@@ -330,7 +330,7 @@ The response body will reflect the chunked nature of the response, so some reass
 message returned by the API.
 
 ```julia
-julia> CC = create_chat(key, "gpt-3.5-turbo",
+julia> CC = create_chat(key, "gpt-4o-mini",
            [Dict("role" => "user", "content"=> "What continent is New York in? Two word answer.")],
        streamcallback = x->println(Dates.now()));
        2023-03-27T12:34:50.428

test/assistants.jl

@@ -32,7 +32,7 @@
 
 # Set API/model
 api_key = ENV["OPENAI_API_KEY"]
-test_model = "gpt-3.5-turbo"
+test_model = "gpt-4o-mini"
 
 # Test functions for the assistant generation/modification/etc.
 @testset "Assistants" begin

test/chatcompletion.jl

@@ -1,6 +1,6 @@
 @testset "chatcompletion" begin
     r = create_chat(ENV["OPENAI_API_KEY"],
-        "gpt-3.5-turbo",
+        "gpt-4o-mini",
         [Dict("role" => "user", "content" => "What is the OpenAI mission?")])
     println(r.response["choices"][begin]["message"]["content"])
     if !=(r.status, 200)
@@ -9,7 +9,7 @@
 
     # with http kwargs (with default values)
     r = create_chat(ENV["OPENAI_API_KEY"],
-        "gpt-3.5-turbo",
+        "gpt-4o-mini",
         [
             Dict("role" => "user",
                 "content" => "Summarize HTTP.jl package in a short sentence."),
@@ -23,7 +23,7 @@ end
 
 @testset "chatcompletion - streaming" begin
     r = create_chat(ENV["OPENAI_API_KEY"],
-        "gpt-3.5-turbo",
+        "gpt-4o-mini",
         [
             Dict("role" => "user",
                 "content" => "What continent is New York in? Two word answer."),