Travis fixes

So, this should make it so that we don't have to track the bin anymore. (aka no more spurious merge conflicts)
It should push up a built node-webkit version for linux, osx and win, though you'll still have to create the config files for settings and whatnot when you start it from the ui, and you'll need a SE jar. Should come with jre and all that stuff though. We should document how to set that up.

All we need is to have an oauth token for releases set up in the `slamdata/slamdata` repo and then transfer it over to the travis settings. Should only need the `public_repo` permission. I'm using the environment variable name `GITHUB_RELEASES_TOKEN`.

You can encrypt it if you'd feel safer that way, though something might have to change in `.travis.yml`, but the only people that should have access to it are the people with admin access to travis, and admin access to `slamdata/slamdata`.