chore(package): update nyc to version 6.4.3 (#103)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -47,7 +47,7 @@
     "cz-conventional-changelog": "1.1.6",
     "in-publish": "2.0.0",
     "mocha": "2.4.5",
-    "nyc": "6.4.2",
+    "nyc": "6.4.3",
     "react": "15.0.2",
     "tslint": "3.9.0",
     "typescript": "1.8.10"