Update to django3!

- This is required to fix some issues with query aggregations as "distinct=True" cannot be set for Sum operations until django 3.0
- Multiple annotations on the same queryset were returning invalid results
- Ref: https://code.djangoproject.com/ticket/10060
- Ref: https://docs.djangoproject.com/en/3.0/topics/db/aggregation/#combining-multiple-aggregations
- django-dbbackup required updating for django3 support
- django-qr-code for now is disabled, a new solution needs to be worked out

InvenTree/InvenTree/settings.py

@@ -101,7 +101,7 @@ INSTALLED_APPS = [
     'crispy_forms',                 # Improved form rendering
     'import_export',                # Import / export tables to file
     'django_cleanup',               # Automatically delete orphaned MEDIA files
-    'qr_code',                      # Generate QR codes
+    #'qr_code',                      # Generate QR codes
     'mptt',                         # Modified Preorder Tree Traversal
     'markdownx',                    # Markdown editing
     'markdownify',                  # Markdown template rendering

InvenTree/InvenTree/urls.py

@@ -8,7 +8,7 @@ Passes URL lookup downstream to each app as required.
 from django.conf.urls import url, include
 from django.contrib import admin
 from django.contrib.auth import views as auth_views
-from qr_code import urls as qr_code_urls
+#from qr_code import urls as qr_code_urls
 
 from company.urls import company_urls
 from company.urls import supplier_part_urls
@@ -99,7 +99,7 @@ urlpatterns = [
 
     url(r'^admin/', admin.site.urls, name='inventree-admin'),
 
-    url(r'^qr_code/', include(qr_code_urls, namespace='qr_code')),
+    #url(r'^qr_code/', include(qr_code_urls, namespace='qr_code')),
 
     url(r'^index/', IndexView.as_view(), name='index'),
     url(r'^search/', SearchView.as_view(), name='search'),

requirements.txt

@@ -1,11 +1,11 @@
 wheel>=0.34.2                   # Wheel
-Django==2.2.10                  # Django package
+Django==3.0.5                  # Django package
 pillow==6.2.0                   # Image manipulation
 djangorestframework==3.10.3     # DRF framework
+django-dbbackup==3.3.0          # Database backup / restore functionality
 django-cors-headers==3.2.0      # CORS headers extension for DRF
 django_filter==2.2.0            # Extended filtering options
 django-mptt==0.10.0             # Modified Preorder Tree Traversal
-django-dbbackup==3.2.0          # Database backup / restore functionality
 django-markdownx==3.0.1         # Markdown form fields
 django-markdownify==0.8.0       # Markdown rendering
 coreapi==2.3.0                  # API documentation