Django - account.models.Account doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS while using pinax-notifications

Question

Integrating client project with pinax-notifications for notification kind of functionality.

  *File "/home/user/Shwetha/ramble/ramble/rambleapp/urls.py", line 56, in <module>
    url(r"^notifications/", include("pinax.notifications.urls", namespace="pinax_notifications")),
  File "/home/user/.local/lib/python3.6/site-packages/django/urls/conf.py", line 34, in include
    urlconf_module = import_module(urlconf_module)
  File "/usr/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/home/user/.local/lib/python3.6/site-packages/pinax/notifications/urls.py", line 3, in <module>
    from .views import NoticeSettingsView
  File "/home/user/.local/lib/python3.6/site-packages/pinax/notifications/views.py", line 5, in <module>
    from .compat import login_required
  File "/home/user/.local/lib/python3.6/site-packages/pinax/notifications/compat.py", line 12, in <module>
    from account.decorators import login_required
  File "/home/user/.local/lib/python3.6/site-packages/account/decorators.py", line 5, in <module>
    from account.utils import handle_redirect_to_login
  File "/home/user/.local/lib/python3.6/site-packages/account/utils.py", line 13, in <module>
    from .models import PasswordHistory
  File "/home/user/.local/lib/python3.6/site-packages/account/models.py", line 26, in <module>
    class Account(models.Model):
  File "/home/user/.local/lib/python3.6/site-packages/django/db/models/base.py", line 116, in __new__
    "INSTALLED_APPS." % (module, name)
RuntimeError: Model class account.models.Account doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS.*

As per the https://github.com/pinax/pinax-notifications#documentation Documentation , it was installed and configured. Encountered the above error while configuring.

Already tried:

1. In settings.py, INSTALLED_APPS section add both pinax and pinax-notifications.
2. Added Sites in INSTALLED_APPS and made SITE_ID=1 in settings.py.
3. verbose_name added in apps.py.

All the above does not seem to solve the problem. Please advise.