removing node 6 from engines

Author: mansona

package.json

@@ -76,7 +76,7 @@
     "stylelint-order": "^1.0.0"
   },
   "engines": {
-    "node": "6.* || 8.* || >= 10.*"
+    "node": "8.* || >= 10.*"
   },
   "ember-addon": {
     "configPath": "tests/dummy/config"