chore(package): update jsdom to version 15.1.0

Closes #318

Author: greenkeeper[bot]

package.json

@@ -53,7 +53,7 @@
     "gulp-stylint": "^4.0.2",
     "gulp-tslint": "^8.1.3",
     "gulp-xo": "^0.20.0",
-    "jsdom": "^13.1.0",
+    "jsdom": "^15.1.0",
     "jshint": "^2.9.7",
     "json-stable-stringify": "^1.0.1",
     "mocha": "^5.2.0",