Upgrade nyc devDependency from ^13.2.0 to ^14.0.0 (#104)

Author: greenkeeper[bot]

package.json

@@ -32,7 +32,7 @@
     "lexicographic-integer": "^1.1.0",
     "mkfiletree": "^1.0.1",
     "monotonic-timestamp": "~0.0.8",
-    "nyc": "^13.2.0",
+    "nyc": "^14.0.0",
     "optimist": "~0.6.1",
     "prebuild": "^8.0.0",
     "prebuild-ci": "^2.0.0",