chore(package): update nyc to version 13.3.0

Closes #15

Author: greenkeeper[bot]

package.json

@@ -37,7 +37,7 @@
     "coveralls": "^3.0.0",
     "eslint-config-xo-lukechilds": "^1.0.0",
     "minimist": "^1.2.0",
-    "nyc": "^11.0.2",
+    "nyc": "^13.3.0",
     "pretty-bytes": "^5.0.0",
     "time-span": "^2.0.0",
     "xo": "^0.19.0"