title: Django does not let me pass empty fields
body: <p>In my forms I have a table with the following columns:</p>
  <pre><code>type = models.CharField(max_length=11, blank=False, null=False)
  name = models.CharField(max_length=50, blank=False, null=False)
  profile_image = models.ImageField(max_length=100, blank=True, null=True)
  terms = models.CharField(max_length=1000, blank=True, null=True)
  bio = models.CharField(max_length=1000, blank=True, null=True)
  </code></pre>
  <p>but when I don't enter anything for bio, it gives me an error message with <code>[23000][1048] Column 'bio' cannot be null</code>.</p>
  <p>Why is this?</p>