[w3c/webauthn] 50bb26: Clean up attestation CDDL

  Branch: refs/heads/vgb-u2f-attestation
  Home:   https://github.com/w3c/webauthn
  Commit: 50bb26e45e3ecd64640459a7222af3aba4bd4e47
      https://github.com/w3c/webauthn/commit/50bb26e45e3ecd64640459a7222af3aba4bd4e47
  Author: Vijay Bharadwaj <vijaybh@users.noreply.github.com>
  Date:   2017-02-13 (Mon, 13 Feb 2017)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Clean up attestation CDDL

Consistent naming across types, stricter specification.