Merge pull request #268 from ember-learn/jw-node-version

Try pinning to Node 12

Author: jenweber

package-lock.json

@@ -90,7 +90,7 @@
     "unified": "^9.2.1"
   },
   "engines": {
-    "node": "10.* || >= 12"
+    "node": "12.*"
   },
   "ember": {
     "edition": "octane"