Convenience script to remove untagged images

[mcastellin]

Adding convenience script that removes untagged images from the local registry. I find myself with a lot of unused and untagged images when I develop new Dockerfiles and I need a fast way to remove old images that are generated during development and left eating up disk space.

[felipecrs]

@mcastellin Adding convenience script that removes untagged images from the local registry. I find myself with a lot of unused and untagged images when I develop new Dockerfiles and I need a fast way to remove old images that are generated during development and left eating up disk space.

How about docker system prune -a?

[mcastellin]

@felipecassiors I never tried the -a option before the removes all unused instead of dangling only. Thanks, I'll give this command a try and see if it serves the same purpose