Change branch to sauce-connect-launcher to fix crash on SauceConnect download

Currently, `sauce-connect-launcher` uses `progress` which does not allow forcing terminal mode in `readline`. I have forked both `sauce-connect-launcher` and `progress` and submitted a pull request (https://github.com/visionmedia/node-progress/pull/23) for `progress` (I'll do the same for `sauce-connect-launcher` as soon as the first one lands). This is a temporary measure until those two packages are fixed.