Update mime requirement from ^1.6.0 to ^2.4.0 (#79)

* Update mime requirement from ^1.6.0 to ^2.4.0

Updates the requirements on [mime](https://github.com/broofa/node-mime) to permit the latest version.
- [Release notes](https://github.com/broofa/node-mime/releases)
- [Changelog](https://github.com/broofa/node-mime/blob/master/CHANGELOG.md)
- [Commits](https://github.com/broofa/node-mime/commits/v2.4.0)

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

* fix breaking change in mime

lib/middlewares/route.js

@@ -29,7 +29,7 @@ module.exports = function(app) {
       return;
     }
 
-    res.setHeader('Content-Type', extname ? mime.lookup(extname) : 'application/octet-stream');
+    res.setHeader('Content-Type', extname ? mime.getType(extname) : 'application/octet-stream');
 
     if (method === 'GET') {
       data.pipe(res).on('error', next);

package.json

@@ -28,7 +28,7 @@
     "chalk": "^2.4.1",
     "compression": "^1.7.3",
     "connect": "^3.6.6",
-    "mime": "^1.6.0",
+    "mime": "^2.4.0",
     "morgan": "^1.9.0",
     "opn": "^5.3.0",
     "serve-static": "^1.13.2"