Adding a Member to an Image

We want to authorize a tenant to access a private image. We issue a PUT request to http://glance.example.com/images/1/members/tenant1. With no body, this will add the membership to the image, leaving existing memberships unmodified and defaulting new memberships to have `can_share` set to `false`. We may also optionally attach a body of the following form:

{'member':
 {'can_share': true}
}

If such a body is provided, both existing and new memberships will have `can_share` set to the provided value (either `true` or `false`). This query will return a 204 ("No Content") status code.