Updated tk-core to v0.18.168

Resolved an issue with Single Sign-On when using NTLM on a domain-bound macOS or Linux computer.

Author: mathurf

core/core_api.yml

@@ -14,5 +14,5 @@
 location:
   type: app_store
   name: tk-core
-  version: v0.18.167
+  version: v0.18.168