Update product versions to 9.1.6

Author: KOTungseth

config/versions.yml

@@ -3,7 +3,7 @@ versioning_systems:
   # Updates for Stack versions are manual
   stack: &stack
     base: 9.0
-    current: 9.1.5
+    current: 9.1.6
 
   # Using an unlikely high version
   # So that our logic that would display "planned" doesn't trigger
@@ -73,7 +73,7 @@ versioning_systems:
   # EDOTs
   edot-collector:
     base: 9.0
-    current: 9.1.5
+    current: 9.1.6
   edot-ios:
     base: 1.0
     current: 1.4.0