Discovery - library additions to support types provided by the caller

[Guitarbum722]

Look into adding functionality to the API to support the caller's own type being deserialized.

This would be similar to a GORM query. For example:

var c customStruct
if err := resource.NeatQuery(&c); err != nil {
    log.Println(err)
}

fmt.Println(c.Name)

Since the SFDC services return JSON, I think this would simply end up wrapping json.Unmarshal.

See what it would take to extend this client sdk and keep it backwards compatible.
Use this issue for conversation, suggestions, etc.