chore(package): update nyc to version 12.0.2

Closes #5

Author: greenkeeper[bot]

package.json

@@ -53,7 +53,7 @@
     "eslint-config-airbnb-base": "^12.1.0",
     "eslint-plugin-import": "^2.8.0",
     "mocha": "^5.0.1",
-    "nyc": "^11.4.1",
+    "nyc": "^12.0.2",
     "rimraf": "^2.6.2",
     "sinon": "^5.0.0"
   },