'Updates an Amazon EBS volume\'s name or mount point. For more
information, see `Resource Management`_.
**Required Permissions**: To use this action, an IAM user must
have a Manage permissions level for the stack, or an attached
policy that explicitly grants permissions. For more
information on user permissions, see `Managing User
Permissions`_.
:type volume_id: string
:param volume_id: The volume ID.
:type name: string
:param name: The new name.
:type mount_point: string
:param mount_point: The new mount point.'

def update_volume(self, volume_id, name=None, mount_point=None):

    params = {'VolumeId': volume_id}
    if (name is not None):
        params['Name'] = name
    if (mount_point is not None):
        params['MountPoint'] = mount_point
    return self.make_request(action='UpdateVolume', body=json.dumps(params))
