chore(package): update standard-version to version 8.0.0

Closes #64

Author: greenkeeper[bot]

package.json

@@ -46,7 +46,7 @@
     "ava": "2.4.0",
     "codecov": "3.6.1",
     "nyc": "15.0.0",
-    "standard-version": "7.0.1",
+    "standard-version": "8.0.0",
     "xo": "0.24.0"
   },
   "peerDependencies": {