[w3c/webauthn] 9f5df0: Make PublicKeyCredentialEntity hierarchy required ...

  Branch: refs/heads/issue-587
  Home:   https://github.com/w3c/webauthn
  Commit: 9f5df060fc78da739e408e4aff2e7edd165e6fe3
      https://github.com/w3c/webauthn/commit/9f5df060fc78da739e408e4aff2e7edd165e6fe3
  Author: Emil Lundberg <emil@yubico.com>
  Date:   2017-11-03 (Fri, 03 Nov 2017)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Make PublicKeyCredentialEntity hierarchy required members required in IDL

This resolves #587.

Summary:

- Make member `PublicKeyCredentialEntity.name` required
- Make member `PublicKeyCredentialUserEntity.id` required
- Make member `PublicKeyCredentialUserEntity.displayName` required
- Remove algorithm step from _§5.1.3 Create a new credential_ that
  instructed to throw an exception if any of the above members were
  missing