fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-INFLIGHT-6095116

package.json

@@ -19,7 +19,7 @@
     "lintfix": "npx eslint --fix *.js test"
   },
   "dependencies": {
-    "tmp": "0.2.1",
+    "tmp": "0.2.2",
     "haraka-constants": "*",
     "haraka-utils": "*"
   },