image.go
func (c *Client) GetImage(imageid string) (*Image, error) {
	url := imagePath(imageid)
	ret := &Image{}
	err := c.client.Get(url, ret, http.StatusOK)
	return ret, err
}
func (c *Client) GetImage(imageid string) (*Image, error) {
	url := imagePath(imageid)
	ret := &Image{}
	err := c.client.Get(url, ret, http.StatusOK)
	return ret, err
}
// GetImage returns an Instance struct where id ==imageid