title: ImportError: cannot import name 'JSONField'
body: <p>I'm getting the error:</p>
  
  <pre><code>  File "/home/mark/Nova/nova/lib/fields.py", line 1, in &lt;module&gt;
      from django.contrib.postgres.fields import JSONField
  ImportError: cannot import name 'JSONField'
  </code></pre>
  
  <p>when I run <code>python manage.py runserver 0.0.0.0:8888</code>. Even though I already have <code>simplejson</code> installed.</p>
  
  <p><code>pip freeze</code> shows,</p>
  
  <pre><code>alabaster==0.7.12
  Babel==2.7.0
  bcdoc==0.16.0
  boto3==0.0.21
  botocore==1.0.0b3
  certifi==2019.9.11
  chardet==3.0.4
  defusedxml==0.6.0
  Django==1.8.2
  django-bulk-update==1.1.4
  django-cors-headers==2.0.2
  django-facebook==6.0.3
  django-pgjsonb==0.0.15
  django-redis==4.2.0
  django-revproxy==0.9.7
  djangorestframework==3.1.3
  djangorestframework-httpsignature==1.0.0
  docutils==0.15.2
  elasticsearch==1.6.0
  facebook-sdk==1.0.0
  filemagic==1.6
  futures==2.2.0
  geopy==1.11.0
  google-api-python-client==1.5.0
  httplib2==0.14.0
  httpsig==1.3.0
  idna==2.8
  Jinja2==2.10.3
  jmespath==0.7.1
  MarkupSafe==1.1.1
  mock==1.0.1
  mongoengine==0.10.0
  msgpack-python==0.5.6
  nose==1.3.7
  oauth2client==2.2.0
  oauthlib==3.1.0
  Pillow==2.8.2
  psycopg2==2.8.4
  py2neo==2.0.8
  pyasn1==0.4.7
  pyasn1-modules==0.2.7
  pycryptodome==3.9.0
  Pygments==2.4.2
  PyJWT==1.7.1
  pymongo==3.0.3
  PySocks==1.7.1
  python-dateutil==2.8.0
  python-social-auth==0.2.10
  python3-memcached==1.51
  python3-openid==3.1.0
  python3-pika==0.9.14
  pytz==2019.3
  redis==2.10.3
  requests==2.2.1
  requests-oauthlib==1.2.0
  rsa==4.0
  simplejson==3.7.3
  six==1.12.0
  snowballstemmer==2.0.0
  Sphinx==1.3.1
  sphinx-rtd-theme==0.1.9
  sphinxcontrib-httpdomain==1.3.1
  treelib==1.3.0
  twilio==5.6.0
  Unidecode==1.1.1
  uritemplate==0.6
  urllib3==1.10.1
  </code></pre>
  
  <p>What would be the fix for this?</p>