title: Django circular import error, trying to allow location to access activity
body: <p>ImportError: cannot import name 'Activity' from partially initialized module 'vacaplusapi.models.activity' (most likely due to a circular import) (/Users/name/project/server/projectname/models/activity.py)</p>
  <p>models/activity.py</p>
  <pre><code>from django.db import models  
  from .activity import Activity
  
  class Activity(models.Model):
  
      activity = models.OneToOneField(Activity, on_delete=models.CASCADE)
      description = models.CharField(max_length=255,)
      date = models.DateField(default=&quot;0000-00-00&quot;,)
      photo = models.ImageField(upload_to=None, height_field=None, width_field=None, max_length=100)
  </code></pre>
  <p>models/location.py</p>
  <ul>
  <li>from vacaplusapi.models import Activity</li>
  <li>from vacaplusapi.models.vacauser import VacaUser</li>
  <li>from django.db import models</li>
  <li>from .vacauser import VacaUser</li>
  </ul>
  <p>class Location(models.Model):</p>
  <pre><code>time = models.DateField(models.DateField(auto_now=False, auto_now_add=False, null=True, blank=True))
  activity = models.ForeignKey(Activity, on_delete=models.DO_NOTHING, related_name=&quot;activity&quot;)
  user = models.ForeignKey(VacaUser, on_delete=models.DO_NOTHING, related_name=&quot;vacauser&quot;)
  title = models.CharField(max_length=50)
  description = models.TextField(max_length=200)
  photo = models.ImageField(upload_to=None, height_field=None, width_field=None, max_length=100)
  </code></pre>