Bump nodejs version to 6+ (#4272)

* let travis build against 3.x

* Cleanup dependencies and bump min version to current LTS

* Makes npm-git push all branches to -preview

* restores releases

* Bumps mime to 2.0.3 (requires node 6+)

* Bumps express to latest version

* Fixes linting issue after upgrade

* Use travis-branch for partial releases

src/Options/index.js

@@ -116,7 +116,7 @@ export interface ParseServerOptions {
   enableSingleSchemaCache: ?boolean; // = false
   /* Sets the number of characters in generated object id's, default 10 */
   objectIdSize: ?number; // = 10
-  /* The port to run the ParseServer. defaults to 1337.@parse/gcs-adapter
+  /* The port to run the ParseServer. defaults to 1337.
   :ENV: PORT */
   port: ?number; // = 1337
   /* The host to serve ParseServer on. defaults to 0.0.0.0 */