title: How to skip some rows that have errors in django-excel using save_to_database()
body: <p>I'm usign <code>django-excel</code> library in my Django project, and I want to skip some rows before save it to the database using the <code>save_to_database()</code> method.</p>
  <p>I have something like the following:</p>
  <pre class="lang-py prettyprint-override"><code>file = form.cleaned_data['file']
  file.save_to_database(
      model=MyModel,
      mapdict = fields,
      initializer=self.choice_func,
  )
  </code></pre>
  <p>All is working ok but I want to validate the data before call <code>save_to_database</code> function. The idea to do it is to add the rows that are not valid in an array and return it to notify the user that those fields not were saved.</p>