I upgraded from v2.2 to 2.3 and I'm receiving the error indicated in the subject when I run Django server.

Stack trace:

Unhandled exception in thread started by <function check_errors..wrapper at 0x7f06651deb70>
Traceback (most recent call last):
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework/settings.py", line 180, in import_from_string
module = import_module(module_path)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/importlib/init.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 986, in _gcd_import
File "", line 969, in _find_and_load
File "", line 958, in _find_and_load_unlocked
File "", line 673, in _load_unlocked
File "", line 665, in exec_module
File "", line 222, in _call_with_frames_removed
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework_json_api/parsers.py", line 9, in
from . import exceptions, renderers, serializers, utils
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework_json_api/serializers.py", line 8, in
from rest_framework_json_api.relations import ResourceRelatedField
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework_json_api/relations.py", line 6, in
import six
ImportError: No module named 'six'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/utils/autoreload.py", line 228, in wrapper
fn(*args, **kwargs)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 125, in inner_run
self.check(display_num_errors=True)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/core/management/base.py", line 359, in check
include_deployment_checks=include_deployment_checks,
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/core/management/base.py", line 346, in _run_checks
return checks.run_checks(**kwargs)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/core/checks/registry.py", line 81, in run_checks
new_errors = check(app_configs=app_configs)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/core/checks/urls.py", line 16, in check_url_config
return check_resolver(resolver)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/core/checks/urls.py", line 26, in check_resolver
return check_method()
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/urls/resolvers.py", line 254, in check
for pattern in self.url_patterns:
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/utils/functional.py", line 35, in get
res = instance.dict[self.name] = self.func(instance)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/urls/resolvers.py", line 405, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/utils/functional.py", line 35, in get
res = instance.dict[self.name] = self.func(instance)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/urls/resolvers.py", line 398, in urlconf_module
return import_module(self.urlconf_name)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/importlib/init.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 986, in _gcd_import
File "", line 969, in _find_and_load
File "", line 958, in _find_and_load_unlocked
File "", line 673, in _load_unlocked
File "", line 665, in exec_module
File "", line 222, in _call_with_frames_removed
File "/vagrant/src/joyrides/joyrides_snake/joyrides_snake/urls.py", line 22, in
url(r'^api/amenities', include('amenities.urls')),
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/django/conf/urls/init.py", line 50, in include
urlconf_module = import_module(urlconf_module)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/importlib/init.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 986, in _gcd_import
File "", line 969, in _find_and_load
File "", line 958, in _find_and_load_unlocked
File "", line 673, in _load_unlocked
File "", line 665, in exec_module
File "", line 222, in _call_with_frames_removed
File "/vagrant/src/joyrides/joyrides_snake/amenities/urls.py", line 3, in
from . import views
File "/vagrant/src/joyrides/joyrides_snake/amenities/views.py", line 1, in
from rest_framework.views import APIView
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework/views.py", line 100, in
class APIView(View):
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework/views.py", line 104, in APIView
parser_classes = api_settings.DEFAULT_PARSER_CLASSES
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework/settings.py", line 223, in getattr
val = perform_import(val, attr)
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework/settings.py", line 168, in perform_import
return [import_from_string(item, setting_name) for item in val]
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework/settings.py", line 168, in
return [import_from_string(item, setting_name) for item in val]
File "/home/ubuntu/.virtualenvs/joyrides_snake/lib/python3.5/site-packages/rest_framework/settings.py", line 184, in import_from_string
raise ImportError(msg)
ImportError: Could not import 'rest_framework_json_api.parsers.JSONParser' for API setting 'DEFAULT_PARSER_CLASSES'. ImportError: No module named 'six'.