[bug] Gulp doesn't clear `dist` folder so deleted files still get uploaded

[tedivm]

In most cases this shouldn't be a problem, as the file won't get loaded if it isn't references anywhere in the uploaded code base, but there are cases during development where it can cause issues (for instance, if uploading code to a private server after removing a program- if the program doesn't exist the scheduler will just kill the process, but if the stale program is uploaded it can result in an unstable system or at a minimum a bunch of errors to the console).