Remove unused jsdom dependency

Author: lukechilds

package.json

@@ -50,7 +50,6 @@
     "babel-preset-es2015": "^6.9.0",
     "coveralls": "^2.11.9",
     "eslint-config-xo-lukechilds": "^1.0.0",
-    "jsdom": "^11.0.0",
     "nyc": "^11.0.2",
     "window": "^3.1.2",
     "xo": "^0.18.2"