build(deps-dev): update lint-staged requirement from ^7.0.0 to ^8.0.0

Updates the requirements on [lint-staged](https://github.com/okonet/lint-staged) to permit the latest version.
- [Release notes](https://github.com/okonet/lint-staged/releases)
- [Commits](https://github.com/okonet/lint-staged/commits/v8.0.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -57,7 +57,7 @@
     "eslint-plugin-import": "^2.8.0",
     "eslint-plugin-mocha": "^5.0.0",
     "husky": "^1.0.1",
-    "lint-staged": "^7.0.0",
+    "lint-staged": "^8.0.0",
     "mocha": "^5.0.0",
     "nyc": "^13.0.1",
     "semantic-release": "^15.0.2"