title: django-tables2 : Error during template rendering
body: <p>I am writing a simplest possible example of django-table2 
  it fails with 
  <code>
  Error during template rendering
  In template /myproject/app/templates/test_table.html, error at line 2
  </code>
  Any clue what's wrong here.  just following document.</p>
  
  <p>context</p>
  
  <p>1   {% load render_table from django_tables2 %}</p>
  
  <p><strong>2 {% render_table table %}</strong></p>
  
  <p>3   </p>
  
  <h2>model.py</h2>
  
  <pre><code>class TestTable1(models.Model):
      col1 = models.CharField(max_length=1, primary_key=True)
      col2 = models.FloatField(blank=True, null=True)
  
      class Meta:
          managed = False
          db_table = 'test_table1'
  
  class TestTable1Tbl(tables.Table):
  
      class Meta:
          model = TestTable1
          attrs = {"class":"paleblue"}
  </code></pre>
  
  <h1>views.py</h1>
  
  <pre><code>def test_table(request):
  
      table = TestTable1Tbl(TestTable1.objects.all())
      RequestConfig(request).configure(table)
      return render(request,"test_table.html",{'table':table})
  </code></pre>
  
  <h1>template</h1>
  
  <p>$ more test_table.html</p>
  
  <pre><code>{% load render_table from django_tables2 %}
  {% render_table table %}
  </code></pre>
  
  <h1>Below is the error message</h1>
  
  <p>During handling of the above exception (could not convert string to float: 'table'), another exception occurred:</p>
  
  <pre><code>        return template.render(context.flatten()) 
  </code></pre>