Streaming support (#61)

* Add streaming support feature (#54)

* Add streaming support feature

removes golangci linting deprecation warnings
See: [Issue #49](https://github.com/sashabaranov/go-gpt3/issues/49)

* remove dead token

* Remove the goroutines from previous implementation

Set up separate test and file for streaming support
Add client code under cmd dir

* Supress CI errors

Need to update import path to test under feature/streaming-support
branch

* suppress linting errors

---------

Co-authored-by: sashabaranov <677093+sashabaranov@users.noreply.github.com>

* remove main.go

* remove code duplication

* use int64

* finalize streaming support

* lint

* fix tests

---------

Co-authored-by: e. alvarez <55966724+ealvar3z@users.noreply.github.com>

README.md

@@ -38,3 +38,51 @@ func main() {
 	fmt.Println(resp.Choices[0].Text)
 }
 ```
+
+Streaming response example:
+
+```go
+package main
+
+import (
+	"errors"
+	"context"
+	"fmt"
+	"io"
+	gogpt "github.com/sashabaranov/go-gpt3"
+)
+
+func main() {
+	c := gogpt.NewClient("your token")
+	ctx := context.Background()
+
+	req := gogpt.CompletionRequest{
+		Model:     gogpt.GPT3Ada,
+		MaxTokens: 5,
+		Prompt:    "Lorem ipsum",
+		Stream:    true,
+	}
+	stream, err := c.CreateCompletionStream(ctx, req)
+	if err != nil {
+		return
+	}
+	defer stream.Close()
+
+	for {
+		response, err := stream.Recv()
+		if errors.Is(err, io.EOF) {
+			fmt.Println("Stream finished")
+			return
+		}
+
+		if err != nil {
+			fmt.Printf("Stream error: %v\n", err)
+			return
+		}
+
+
+		fmt.Printf("Stream response: %v\n", response)
+
+	}
+}
+```