anchor.diff:  
   The `data` attribute is a key value object with strings for keys and values. It is used to attach extra information about the message and the context that it was created in.
   
  -## POST /api/messages{?person_id,conversation_id}
  -
  -+ Parameters
  -    + person_id (required UUID `10ce24de-23f6-433f-9a71-255cffffa96f`)
  -    + conversation_id (optional UUID `10ce24de-23f6-433f-9a71-255cffffa96f`)
  -
  -+ Request
  -    + Headers
  -
  -            Accept: application/hal+json
  +*TODO* The values of the data object determine special properties of the message.
  +
  +
  +## POST /api/messages
  +
  ++ Request
  +    + Headers
  +
  +            Accept: application/hal+json
  +            Content-Type: application/x-www-form-urlencoded
   
       + Body
   
               {
                   "content": "Hello World!",
  +                "conversation_id": "10ce24de-23f6-433f-9a71-255cffffa96f",
                   "data": {
                       "foo": "bar"
  -                }
  +                },
  +                "person_id": "10ce24de-23f6-433f-9a71-255cffffa96f"
               }
   
   + Response 201 (application/hal+json)
  
positive.code: 
  # Helpful API
  
  
  ## Authentication
  
  
negative.code: - created
  - updated
  
  + Model
  
      + Body
  
              {
                  "id": "XXX"
              }
  
  ### Fetch an account [GET]
  
  + Response 200
  
      [Account][]
  
  ### Update an account [PATCH]
  
  + Request
  
      + Body
  
              {
                  "name": ""
              }
  
  + Response 200
  
      [Account][]
  
  
  ## POST /api/accounts/{account_id}/memberships
  
  + Request
  
      + Headers
  
              Accept: application/hal+json
  
      + Body
  
              {
                  "role": "admin",
                  "user_id": "XXX",
              }
  
  + Response 201 (application/hal+json)
  
      + Headers
  
              Location: <>
  
      + Body
  
              {
                  "id": "XXX",
                  "type": "membership",
                  "role": "admin"
                  "user_id": "XXX",
              }
  
  
  ## Membership [/api/accounts/{account_id}/memberships/{id}]
  
  - id
  - role
  