raise ImproperlyConfigured("settings.DATABASES is improperly configured. "
django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'HOST': os.environ.get('PGHOST'),
        'NAME': os.environ.get('PGDATABASE'),  
        'USERNAME': os.environ.get('PGUSER'),
        'PASSWORD': os.environ.get('PGPASSWORD'),
        'PORT':os.environ.get('PGPORT')
    }
}