title: django-tables2 exclude & field not working
body: <p>I'm new to django and stumbling through creating my first site. I'm using django-tables2 to display a table and it appears to be working (the table shows up, it's sortable). </p>
  
  <p>Except I can't seem to customize anything. Exclude, field and sequence don't work. Can't change column verbose names.</p>
  
  <p>TABLE:</p>
  
  <pre><code>import django_tables2 as tables
  from sl_overview.models import DailyslSumm
  
  class slsummTable(tables.Table):
  
      class Meta:
          model = DailyslSumm
          exclude = ('index')
  </code></pre>
  
  <p>VIEW:</p>
  
  <pre><code>class sl_summ(SingleTableView):
  
      model = DailyslSumm
      context_object_name = 'slsummdb'
      table_class = slsummTable
  </code></pre>
  
  <p>TEMPLATE:</p>
  
  <pre><code>{% load render_table from django_tables2 %}
  {% render_table slsummdb %}
  </code></pre>
  
  <p>The exclude in the code above doesn't work. The column is still there. Using field doesn't adjust columns either. I'm sure I'm missing something simple, thanks for any help.</p>