build(deps-dev): bump @types/mocha from 7.0.2 to 8.0.0 (#54)

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

package.json

@@ -14,7 +14,7 @@
   "devDependencies": {
     "@opentelemetry/api": "^0.9.0",
     "@opentelemetry/tracing": "^0.9.0",
-    "@types/mocha": "^7.0.2",
+    "@types/mocha": "^8.0.0",
     "@types/node": "^14.0.14",
     "@typescript-eslint/eslint-plugin": "^2.34.0",
     "c8": "^7.2.0",