title: django.core.exceptions.ImproperlyConfigured: 'django_mongodb_engine' isn't an available database backend
body: <p>I'm unable to run django mongo engine properly.</p>
  
  <p>My database entry in settings.py is </p>
  
  <pre><code>DATABASES = {
  'default': {
      'ENGINE': 'django_mongodb_engine',
      'NAME': 'local',
  }
  }
  </code></pre>
  
  <p>and my pip freeze result is</p>
  
  <pre><code>Django==1.8.2
  django-mongodb-engine==0.5.2
  djangotoolbox==1.6.2
  pymongo==3.0.2
  </code></pre>
  
  <p>error while running</p>
  
  <pre><code>python manage.py runserver
  </code></pre>
  
  <p>is </p>
  
  <pre><code>django.core.exceptions.ImproperlyConfigured: 'django_mongodb_engine' isn't an available database backend.
  Try using 'django.db.backends.XXX', where XXX is one of:
  u'base', u'mysql', u'oracle', u'postgresql_psycopg2', u'sqlite3'
  Error was: cannot import name BaseDatabaseFeatures
  </code></pre>
  
  <p>Any suggestions how to solve this.</p>