Add SetBasicAuth function for HTTP Auth

@@ -147,6 +147,12 @@ func (b *BeegoHttpRequest) Setting(setting BeegoHttpSettings) *BeegoHttpRequest
 	return b
 }
 
+// SetBasicAuth sets the request's Authorization header to use HTTP Basic Authentication with the provided username and password.
+func (b *BeegoHttpRequest) SetBasicAuth(username, password string) *BeegoHttpRequest {
+	b.req.SetBasicAuth(username, password)
+	return b
+}
+
 // SetEnableCookie sets enable/disable cookiejar
 func (b *BeegoHttpRequest) SetEnableCookie(enable bool) *BeegoHttpRequest {
 	b.setting.EnableCookie = enable

@@ -120,6 +120,18 @@ func TestWithCookie(t *testing.T) {
 	}
 }
 
+func TestWithBasicAuth(t *testing.T) {
+	str, err := Get("http://httpbin.org/basic-auth/user/passwd").SetBasicAuth("user", "passwd").String()
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log(str)
+	n := strings.Index(str, "authenticated")
+	if n == -1 {
+		t.Fatal("authenticated not found in response")
+	}
+}
+
 func TestWithUserAgent(t *testing.T) {
 	v := "beego"
 	str, err := Get("http://httpbin.org/headers").SetUserAgent(v).String()