re-simplify the documentation URL

- dev version = "latest"
- stable version = "x.y.z"
- Requires an explicit docs version release for every software release

InvenTree/InvenTree/tasks.py

@@ -301,7 +301,9 @@ def send_email(subject, body, recipients, from_email=None):
 
     offload_task(
         'django.core.mail.send_mail',
-        subject, body,
+        subject,
+        body,
         from_email,
         recipients,
+        fail_silently=False,
     )

InvenTree/InvenTree/version.py

@@ -11,11 +11,6 @@ import common.models
 # InvenTree software version
 INVENTREE_SW_VERSION = "0.6.0 dev"
 
-# InvenTree documentation version
-# For 'dev' branch this must read "latest"
-# For 'stable' branch this must match INVENTREE_SW_VERSION
-INVENTREE_DOCS_VERSION = "latest"
-
 # InvenTree API version
 INVENTREE_API_VERSION = 15
 
@@ -119,7 +114,10 @@ def inventreeDocsVersion():
     
     """
 
-    return INVENTREE_DOCS_VERSION
+    if isInvenTreeDevelopmentVersion():
+        return "latest"
+    else:
+        return INVENTREE_SW_VERSION
 
 
 def isInvenTreeUpToDate():