chore(package): update nyc to version 12.0.2

Closes #26

Author: greenkeeper[bot]

package.json

@@ -10,7 +10,7 @@
   "devDependencies": {
     "ava": "^0.19.0",
     "coveralls": "2.x",
-    "nyc": "^10.0.0",
+    "nyc": "^12.0.2",
     "reshape": "0.4.2",
     "snazzy": "^6.0.0",
     "standard": "10.0.0"