Instead of expanding the registry name we're looking for to a full URL,
strip entries in the authconfig down to just the hostname.
Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>
[`filters` is a json encoded value of the filters (a map[string][string]) to process on the images list. ][1]
The tricky thing is that we must convert boolean value to string and any filter value to list to make a `map[string][string]` json format
[1]: https://docs.docker.com/reference/api/docker_remote_api_v1.14/#list-images