chore(package): update nyc to version 14.1.1

Closes #38

Author: greenkeeper[bot]

package.json

@@ -39,7 +39,7 @@
     "istanbul": "^0.4.5",
     "jsdom": "^11.0.0",
     "mocha": "^5.0.0",
-    "nyc": "^12.0.2",
+    "nyc": "^14.1.1",
     "preact": "^8.1.0",
     "rollup": "^0.59.0",
     "rollup-plugin-babel": "^3.0.1"