Add customizable redirection URL after login and logout.

test_oauth/views.py

 from django.shortcuts import redirect
 from django.contrib import auth
 from django.views.decorators.cache import never_cache
+from django.conf import settings
 
 from test_oauth.session import TESTOAuth2Session
 
@@ -18,7 +19,7 @@ def login(request, next=None):
 def logout(request):
     if request.user.is_authenticated():
         auth.logout(request)
-    return redirect("/")
+    return redirect(getattr(settings, 'TEST_OAUTH_REDIRECT', '/'))
 
 
 @never_cache
@@ -32,4 +33,4 @@ def callback(request):
 
     auth.login(request, auth.authenticate(**session.profile))
 
-    return redirect('/')
+    return redirect(getattr(settings, 'TEST_OAUTH_REDIRECT', '/'))