chore(package): update nyc to version 13.2.0

Closes #69

Author: greenkeeper[bot]

package.json

@@ -32,7 +32,7 @@
     "coveralls": "^3.0.1",
     "eslint": "^4.19.1",
     "eslint-config-pedant": "^1.0.0",
-    "nyc": "^11.7.1",
+    "nyc": "^13.2.0",
     "proxyquire": "^2.0.1",
     "sinon": "^5.0.4"
   },