chore(package): update jsdom to version 15.0.0

Closes #10

Author: greenkeeper[bot]

package.json

@@ -85,7 +85,7 @@
     "gh-pages": "^2.0.1",
     "html": "^1.0.0",
     "husky": "^1.3.1",
-    "jsdom": "^13.1.0",
+    "jsdom": "^15.0.0",
     "json-loader": "^0.5.7",
     "lint-staged": "^8.1.0",
     "mini-css-extract-plugin": "^0.5.0",