chore(package): update nyc to version 12.0.2

Closes #52

Author: greenkeeper[bot]

package.json

@@ -57,7 +57,7 @@
     "gulp": "^3.9.1",
     "gulplog": "^1.0.0",
     "husky": "^0.14.1",
-    "nyc": "^11.0.3",
+    "nyc": "^12.0.2",
     "rimraf": "^2.6.1",
     "source-map-support": "^0.5.0",
     "standard-version": "^4.2.0",