내 Go 프로그램이 RabbitMQ 라이브러리를 올바르게 사용하지 않는 이유는 무엇입니까?

import (
    "github.com/streadway/amqp"
)

cannot find package "github.com/streadway/amqp" in any of:
    /usr/local/go/src/github.com/streadway/amqp (from $GOROOT)
    /Users/username/go/src/github.com/streadway/amqp (from $GOPATH)

go get github.com/streadway/amqp

conn, err := amqp.Dial("amqp://guest:guest@localhost:5672/")

dial tcp 127.0.0.1:5672: getsockopt: connection refused

systemctl status rabbitmq-server
systemctl start rabbitmq-server

ch, err := conn.Channel()
q, err := ch.QueueDeclare("hello", false, false, false, false, nil)

channel/connection is not open

conn, _ := amqp.Dial("amqp://guest:guest@localhost:5672/")
defer conn.Close()

ch, _ := conn.Channel()
defer ch.Close()

q, _ := ch.QueueDeclare("hello", false, false, false, false, nil)

err = ch.Publish("", "hello", false, false, amqp.Publishing{
    ContentType: "text/plain",
    Body:        []byte("Hello World!"),
})

no route to host

err := ch.Publish(
    "amq.direct", // exchange
    q.Name,       // routing key
    false,        // mandatory
    false,
    amqp.Publishing {
        ContentType: "text/plain",
        Body:        []byte("Hello World!"),
})