[BREAKING] require node 10 or higher (lowest supported version)

Author: lukemelia

package.json

@@ -33,7 +33,7 @@
     "mocha": "^3.2.0"
   },
   "engines": {
-    "node": ">= 4"
+    "node": ">= 10"
   },
   "ember-addon": {}
 }