[w3c/webauthn] d5d88e: Adding u2f appid extension

  Branch: refs/heads/acz
  Home:   https://github.com/w3c/webauthn
  Commit: d5d88e40a27985967906c76d18fc5142b9397076
      https://github.com/w3c/webauthn/commit/d5d88e40a27985967906c76d18fc5142b9397076
  Author: Alexei Czeskis <aczeskis@google.com>
  Date:   2016-10-05 (Wed, 05 Oct 2016)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Adding u2f appid extension

Closes Issue #216