chore(package): update standard-version to version 3.0.0 (#44)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -56,7 +56,7 @@
     "mocha": "^3.0.0",
     "nyc": "^8.1.0",
     "standard": "^8.0.0",
-    "standard-version": "^2.1.2"
+    "standard-version": "^3.0.0"
   },
   "files": [
     "index.js"