v0.8.0

Added

• A plaintext-declaration-api suite for the Collection plaintext member and
  its indexes declaration: plaintext.indexes persists and echoes on POST and
  PUT create, plaintext and encryption both present is 400 on create and on
  update in either direction (an empty plaintext still excludes), malformed
  plaintext is 400, plaintext is added, changed, and emptied with {} on an
  existing Collection, and a unique index conflict is 409 at write time and
  when promoting an attribute to unique over colliding Resources. The suite is
  optional until the spec text for plaintext lands.