Patch a few small deprecated operations so that the site works under Django 2.0 as well

entries/migrations/0011_auto_20171120_1108.py

@@ -6,6 +6,7 @@ from django.db import migrations
 
 
 class Migration(migrations.Migration):
+    atomic = False
 
     dependencies = [
         ('entries', '0010_entry_tags'),

lemoncurry/templatetags/lemoncurry_tags.py

@@ -52,7 +52,7 @@ def nav_left(request):
 
 @register.inclusion_tag('lemoncurry/tags/nav.html')
 def nav_right(request):
-    if request.user.is_authenticated():
+    if request.user.is_authenticated:
         items = (
             MenuItem(label='admin', icon='fas fa-cog', url='admin:index'),
             MenuItem(label='log out', icon='fas fa-sign-out-alt', url='lemonauth:logout'),