chore(deps): update dependency mime to v4

Author: renovate[bot]

package.json

@@ -18,7 +18,7 @@
     "egg-ci": "^1.8.0",
     "eslint": "^5.0.1",
     "eslint-config-egg": "^7.0.0",
-    "mime": "1"
+    "mime": "4"
   },
   "homepage": "https://github.com/node-modules/buffer-type",
   "repository": {