title: Loopback sends wrong datatype
body: <p>In my mongodb i have several arrays, but when i load those arrays from the database they strangley are objects instead of arrays.</p>
  
  <p>This strange behaviour is since a couple of days, before everything worked fine and i got arrays out of the database.</p>
  
  <p>Has loopback some strange flags which are set automatically, that transform my arrays to objects or something like that?</p>
  
  <p>Currently I have the newest versions in all my packages and have already tried to use older versions, but nothing changes this behaviour.</p>
  
  <p>At first there was also a problem with the saving of the arrays, sometimes they were saved as objects, but since I removed all null objects from the database, only arrays were saved.</p>
  
  <p>The problem occurs with the sections array</p>
  
  <p>my model json is:</p>
  
  <pre><code>{
    "name": "Track",
    "plural": "Tracks",
    "base": "PersistedModel",
    "idInjection": true,
    "options": {
      "validateUpsert": true
    },
    "properties": {
      "alreadySynced": {
        "type": "boolean"
      },
      "approved": {
        "type": "boolean"
      },
      "deletedByClient": {
        "type": "boolean",
        "default": false
      },
      "sections": {
        "type": "object",
        "required": true
      },
      "type": {
        "type": "string"
      },
      "email": {
        "type": "string",
        "default": ""
      },
      "name": {
        "type": "string",
        "default": "Neuer Track"
      },
      "reason": {
        "type": "string",
        "default": ""
      },
      "date": {
        "type": "date"
      },
      "duration": {
        "type": "number",
        "default": 0
      },
      "correctnessscore": {
        "type": "number",
        "default": 0
      },
      "evaluation": {
        "type": "object"
      }
    },
    "validations": [],
    "relations": {},
    "acls": [],
    "methods": {}
  }
  </code></pre>
  
  <p>I have also already tried to change the type object to array but without success</p>