Delete EC2-compatible credentials

    CLI Examples:

    .. code-block:: bash

        salt '*' keystone.ec2_credentials_delete \
        860f8c2c38ca4fab989f9bc56a061a64 access_key=5f66d2f24f604b8bb9cd28886106f442

        salt '*' keystone.ec2_credentials_delete name=admin \
        access_key=5f66d2f24f604b8bb9cd28886106f442

def ec2_credentials_delete(user_id=None, name=None, access_key=None,
                           profile=None, **connection_args):
    '''
    Delete EC2-compatible credentials

    CLI Examples:

    .. code-block:: bash

        salt '*' keystone.ec2_credentials_delete \
        860f8c2c38ca4fab989f9bc56a061a64 access_key=5f66d2f24f604b8bb9cd28886106f442

        salt '*' keystone.ec2_credentials_delete name=admin \
        access_key=5f66d2f24f604b8bb9cd28886106f442
    '''
    kstone = auth(profile, **connection_args)

    if name:
        user_id = user_get(name=name, profile=None, **connection_args)[name]['id']
    if not user_id:
        return {'Error': 'Could not resolve User ID'}
    kstone.ec2.delete(user_id, access_key)
    return 'ec2 key "{0}" deleted under user id "{1}"'.format(access_key,
                                                              user_id)