fix(package): update jsdom to version 15.0.0

Closes #39

Author: greenkeeper[bot]

package.json

@@ -33,7 +33,7 @@
     "ember-cli-addon-tests": "^0.11.0",
     "ember-cli-babel": "^6.8.2",
     "jquery": "^3.3.1",
-    "jsdom": "^11.10.0",
+    "jsdom": "^15.0.0",
     "mocha": "^5.1.1",
     "request": "^2.85.0",
     "rsvp": "^4.7.0"