Send 1.15.0 notifications to stable

1.15.1 was supposed to come out a week ago
It didn't and probably won't within the next week
So we can just deliver this one

Author: GarboMuffin

docs/version.json

@@ -1,5 +1,5 @@
 {
-  "latest": "1.14.4",
+  "latest": "1.15.0",
   "latest_unstable": "1.15.0",
   "oldest_safe": "1.8.0"
 }