Specify that Value() return a map on the lists about firego

[zabawaba99]

I don't mind adding a snippet in the README to describe this behavior. It's a Firebase specific thing though.

For example,

package main

import (
	"log"

	"github.com/zabawaba99/firego"
)

func main() {
	fb := firego.New("https://my-app.firebaseio.com/issue62", nil)
	// auth configuration left out intentionally

	testData := map[string]string{
		"1": "tkn1",
		"2": "tkn1",
		"3": "tkn2",
		"4": "tkn3",
		"5": "tkn4",
		"6": "tkn5",
	}

	if err := fb.Set(testData); err != nil {
		panic(err)
	}

	var v interface{}
	if err := fb.Value(&v); err != nil {
		log.Fatalf("cannot get value %s", err)
	}

	log.Printf("Before deletion %#v\n", v)

	fb.Child("2").Remove()
	fb.Child("3").Remove()
	fb.Child("5").Remove()

	if err := fb.Value(&v); err != nil {
		log.Fatalf("cannot get value %s", err)
	}

	log.Printf("After deletion %#v\n", v)
}

Prints out

$ go run issue62.go
2017/08/26 17:03:00 Before deletion []interface {}{interface {}(nil), "tkn1", "tkn1", "tkn2", "tkn3", "tkn4", "tkn5"}
2017/08/26 17:03:00 After deletion map[string]interface {}{"6":"tkn5", "1":"tkn1", "4":"tkn3"}

---

IIRC, if you end up deleting for than X amount of values inside the array, then it's returned as a map

[zabawaba99]

Closing issue as repository is being archived.