title: Mobx Observable Array not updated
body: <p>I am declaring a observable array in the following way in reactjs using mobx</p>
  
  <pre><code>@observable cacheditems
  
  constructor() {
      this.cacheditems  =   []
  </code></pre>
  
  <p>Now I am retrieving the data from pouch-db when offline as follows:</p>
  
  <pre><code>var items = []
  db.allDocs({include_docs: true}, function(err, docs) {
                  docs.rows.map((obj, id) =&gt; {
                      items.push(obj.doc)
                  })
              })
  
  
   this.cacheditems = items
  </code></pre>
  
  <p>But the data is not set. When I try to get the data for rendering its a empty array.</p>