Bump to nyc@13

Resolves #9

Author: strugee

package.json

@@ -24,7 +24,7 @@
   "devDependencies": {
     "coveralls": "^3.0.0",
     "jshint": "^2.9.4",
-    "nyc": "^11.2.1",
+    "nyc": "^13.1.0",
     "vows": "^0.8.1"
   },
   "dependencies": {