Bump config from 3.3.3 to 3.3.8

Bumps [config](https://github.com/node-config/node-config) from 3.3.3 to 3.3.8.
- [Release notes](https://github.com/node-config/node-config/releases)
- [Changelog](https://github.com/node-config/node-config/blob/master/History.md)
- [Commits](https://github.com/node-config/node-config/commits/v3.3.8)

---
updated-dependencies:
- dependency-name: config
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

package.json

@@ -5,7 +5,7 @@
   "author": "Francois Zaninotto",
   "dependencies": {
     "async": "3.2.4",
-    "config": "3.3.3",
+    "config": "3.3.8",
     "connect-flash": "0.1.1",
     "cookie-parser": "^1.4.3",
     "cookie-session": "^2.0.0-beta.3",