cannot run aerospike go example

I'm trying to run an aerospike go example:

package main

    import (
    "github.com/aerospike/aerospike-client-go"
    "fmt"
    )

    func panicOnError(err error) {
    if err != nil {
        panic(err)
    }
    }

     func main() {
    // define a client to connect to
    client, err := NewClient("127.0.0.1", 3000)
    panicOnError(err)

    key, err := NewKey("test", "aerospike", "key")
    panicOnError(err)

    // define some bins with data
    bins := BinMap{
        "bin1": 42,
        "bin2": "An elephant is a mouse with an operating system",
        "bin3": []interface{}{"Go", 2009},
    }

    // write the bins
    err = client.Put(nil, key, bins)
    panicOnError(err)

    // read it back!
    rec, err := client.Get(nil, key)
    panicOnError(err)

    fmt.Printf("%#v\n", *rec)

    // delete the key, and check if key exists
    existed, err := client.Delete(nil, key)
    panicOnError(err)
    fmt.Printf("Record existed before delete? %v\n", existed)
}

But I get an error:

Unresolved reference NewClient... 
and many more...

I've run the command:

go get github.com/aerospike/aerospike-client-go

and it has downloaded the package on the disk.

Can you help?