chore: Upgrade 'standard-version' to v8

Author: medikoo

package.json

@@ -59,7 +59,7 @@
     "lint-staged": "^10.2.2",
     "prettier": "^2.0.5",
     "sinon": "^8.1.1",
-    "standard-version": "^7.1.0"
+    "standard-version": "^8.0.0"
   },
   "scripts": {
     "commitlint": "commitlint -f HEAD@{15}",