Comment 1 for bug 1462937

I don't have much of a preference on this. On the one hand, utilizing it rather than reinventing the wheel for checking the json format is probably better, and it's not a large overhead since a lot of openstack also has it as a dependency. As you say, though, we're basically using it to check two values in one place in the code, which seems like overkill:
    https://github.com/openstack/glance_store/blob/cb4c615e8495590983330b01c0cdaa272abf1181/glance_store/_drivers/filesystem.py#L72-82