def update(member_address, options={})
      params = {:address => member_address}
      Mailgun.submit :put, list_member_url(member_address), params.merge(options)
    end
def update(member_address, options={})
      params = {:address => member_address}
      Mailgun.submit :put, list_member_url(member_address), params.merge(options)
    end
Update a mailing list member with a given address