Insecure registries

For the best security, Cup only connects to registries over SSL (HTTPS) by default. However, for people running a local registry that haven't configured SSL, this may be a problem.

To solve this problem, cup.json has an "insecure_registries" option which allows you to specify exceptions

Here's what it looks like:

{
    "insecure_registries": ["<INSECURE_REGISTRY_1>", "<INSECURE_REGISTRY_2>"],
    // Other options
}