title: Django, matching query does not exist
body: <p>I am new to Django. When I run the command <code>python manage.py runserver</code> on pycharm, I get the error message like </p>
  
  <pre><code>2017-12-03 05:09:56,952 - INFO - server - Listening on endpoint 
  tcp:port=8000:interface=127.0.0.1
  Internal Server Error: /
  Traceback (most recent call last):
  File "/Users/mac/anaconda/lib/python3.6/site-packages/django/core/handlers/exception.py", line 41, in innerresponse = get_response(request)
  File "/Users/mac/anaconda/lib/python3.6/site-packages/django/core/handlers/base.py", line 187, in _get_response response = self.process_exception_by_middleware(e, request)
  File "/Users/mac/anaconda/lib/python3.6/site-packages/channels/handler.py", line 243, in process_exception_by_middleware
  return super(AsgiHandler,self).process_exception_by_middleware(exception, request)
  File "/Users/mac/anaconda/lib/python3.6/site-packages/django/core/handlers/base.py", line 185, in _get_response response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users/mac/PycharmProjects/590/flightmate/webapp/views.py", line 180, in index airlines = RecordSet.objects.get(name="airline")
  File "/Users/mac/anaconda/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
  return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/Users/mac/anaconda/lib/python3.6/site-packages/django/db/models/query.py", line 380, in get self.model._meta.object_name
  webapp.models.DoesNotExist: RecordSet matching query does not exist.
  </code></pre>
  
  <p>The code of <code>models.py</code> is :</p>
  
  <pre><code>from __future__ import unicode_literals
  import uuid
  import datetime
  from django.db import models
  
  class RecordSet(models.Model):
  name = models.CharField(max_length=512)
  value = models.TextField()
  def __unicode__(self):
      return "{0}: {1}".format(self.name, self.value)
  </code></pre>
  
  <p>And the parent directory of <code>models.py</code> is the directory <code>webapp</code>. Any suggestions is appreciated, thanks!</p>