fix rest_framework urls, other quick fixes

oser_cs/api/urls.py

 """API routers."""
-from django.urls import path, include
 from rest_framework import routers
 
 from .views import users, tutoring
 
 app_name = 'api'
 
-urlpatterns = [
-    path('api-auth/', include(
-        'rest_framework.urls', namespace='rest_framework')),
-]
+urlpatterns = []
 
 # Create your routes here
 

oser_cs/oser_cs/urls.py

@@ -24,5 +24,7 @@ urlpatterns = [
     url(r'^admin/', admin.site.urls),
     url(r'^api/', include('api.urls')),
     url(r'^api/docs/', include_docs_urls(title='OSER_CS API')),
+    url('api-auth/', include(
+        'rest_framework.urls', namespace='rest_framework')),
     url(r'^$', TemplateView.as_view(template_name='index.html')),
 ]

oser_cs/users/signals.py

@@ -9,7 +9,6 @@ from .models import User, Profile
 @receiver(post_save, sender=User)
 def create_profile_for_new_user(sender, created, instance, **kwargs):
     """Automatically creates a new profile for a newly created user."""
-    if created:
-        if instance.profile_type:
+    if created and instance.profile_type:
         model = Profile.get_model(instance.profile_type)
         model.objects.create(user=instance)

oser_cs/utils.py

@@ -2,10 +2,10 @@
 
 
 def modify_fields(**kwargs):
-    """Modify the fields of a superclass.
+    """Modify the fields of an inherited model.
 
-    Caution: will affect the superclass' fields too. It is preferable to
-    restrict the usage to cases when the superclass is abstract.
+    Caution: will affect the inherited model's fields too. It is preferable to
+    restrict the usage to cases when the inherited model is abstract.
 
     Example
     -------