Tests for muriqui

[chinchliff]

• Round trip valid annotation json with random characters -- result should be identical JSON (not necessarily isomorphic)
• Round trip valid annotation json with random Unicode -- result should be identical JSON (not necessarily isomorphic)
• Attempt to read invalid entries, which should fail gracefully. Ways of being invalid:
  • invalid datetime string for oa:annotatedAt
  • bad body value
  • poorly formed annotation
  • poorly formed entity
  • poorly formed target
  • conflict in target reference
  • specifiers in included set also in exclude
  • no specifiers in include