restful-go: update ex-3 instructions and solution

restful-go/README.md

@@ -35,6 +35,8 @@ Here are some examples of opensource frameworks:
 
 Using the standard library to create a client that calls your new web endpoint. To connect to you server, you will need to run your server in one different and the client app in a different terminal window.
 
+_Extra Practice:_ Lots of companies use [Postman](https://www.postman.com/) to test their service endpoints. Build a client in postman that will call your server. Save you postman solution and generate a go client from the [Postman UI](<F5>nhttps://learning.postman.com/docs/sending-requests/generate-code-snippets/). Does you generated go code match the one you build?
+
 ### [Exercise 4](/ex-4-test/framework_tests.go)
 
 Using the [httptest](https://pkg.go.dev/net/http/httptest#example-ResponseRecorder) package add some tests for at least one of our newly created endpoints. You should have one test that checks for a 200s class error and one that tests for a 400s class error. Add additional test validations as time allows.

restful-go/ex-3-clients/client.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+func main() {
+
+	client := http.Client{
+		Timeout: time.Second * 2,
+	}
+
+	req, err := http.NewRequest("GET", "http://localhost:3000/3weeks-go/testGet", nil)
+	if err != nil {
+		panic(err)
+	}
+	body, err := client.Do(req)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println(body)
+}