Provide a place to hang onto results of --list-[locations|sizes|images]
    so we don't have to go out to the API and get them every time.

def _cache_provider_details(conn=None):
    '''
    Provide a place to hang onto results of --list-[locations|sizes|images]
    so we don't have to go out to the API and get them every time.
    '''
    DETAILS['avail_locations'] = {}
    DETAILS['avail_sizes'] = {}
    DETAILS['avail_images'] = {}
    locations = avail_locations(conn)
    images = avail_images(conn)
    sizes = avail_sizes(conn)

    for key, location in six.iteritems(locations):
        DETAILS['avail_locations'][location['name']] = location
        DETAILS['avail_locations'][key] = location

    for key, image in six.iteritems(images):
        DETAILS['avail_images'][image['name']] = image
        DETAILS['avail_images'][key] = image

    for key, vm_size in six.iteritems(sizes):
        DETAILS['avail_sizes'][vm_size['name']] = vm_size
        DETAILS['avail_sizes'][key] = vm_size