chore(package): update nyc to version 15.0.1

Closes #5

Author: greenkeeper[bot]

package.json

@@ -56,7 +56,7 @@
     "eslint-plugin-jsx-a11y": "^6.2.3",
     "eslint-plugin-react": "^7.14.3",
     "husky": "^3.0.2",
-    "nyc": "^14.1.1",
+    "nyc": "^15.0.1",
     "rimraf": "^2.6.3",
     "semantic-release": "^15.13.19"
   },