title: Why is this json schema invalid? using "any" type
body: <pre><code>{
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "my json api",
      "description": "my json api",
      "type": "object",
      "properties": {
          "my_api_response": {
             "type": "object",
              "properties": {
                  "MailboxInfo": {
                      "type": "array",
                      "items": {
                          "type": "object",
                          "properties": {
                              "ADSyncLinkEnabled": {
                                  "type": "any"
                              }
                          }
                      }
                  }
              }
          }
      },
      "required": ["response"]
  }
  </code></pre>
  
  <p>I am using python jsonschema 2.0.0 and it gives me the following error:</p>
  
  <pre><code>{u'type': u'object', u'properties': {u'ADSyncLinkEnabled': {u'type': u'any'}}} is not valid under any of the given schemas
  </code></pre>