tools: update package.json engine field

PR-URL: #14165
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Benjamin Gruenbaum <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Jeremiah Senkpiel <[email protected]>
Reviewed-By: Refael Ackermann <[email protected]>
Reviewed-By: Gibson Fahnestock <[email protected]>
Reviewed-By: James M Snell <[email protected]>

tools/doc/package.json

@@ -4,7 +4,7 @@
   "description": "Internal tool for generating Node.js API docs",
   "version": "0.0.0",
   "engines": {
-    "node": ">=0.6.10"
+    "node": ">=6"
   },
   "dependencies": {
     "marked": "^0.3.5",