Update dependency boilerplate-update to v0.31.15

Author: renovate-bot

package-lock.json

@@ -38,7 +38,7 @@
     "src"
   ],
   "dependencies": {
-    "boilerplate-update": "0.31.14",
+    "boilerplate-update": "0.31.15",
     "debug": "^4.1.1",
     "execa": "^3.4.0",
     "fs-extra": "^8.0.0",