Update package values

Error message in Heroku: "Unable to download node 16.1.0; does it exist?"

Author: amyrlam

Diff for: package.json

@@ -107,8 +107,8 @@
   },
   "engines": {
     "node": "10.* || >= 12",
-    "npm": "5",
-    "yarn": "^1.22.0"
+    "npm": "7",
+    "yarn": "1.22.10"
   },
   "ember": {
     "edition": "octane"
@@ -123,7 +123,7 @@
     "abortcontroller-polyfill/dist/cjs-ponyfill"
   ],
   "volta": {
-    "node": "12.16.1",
-    "yarn": "1.22.4"
+    "node": "14.17.0",
+    "yarn": "1.22.10"
   }
 }