Recent refactoring broke the rake tasks

[phs]

Who's got two thumbs and didn't see the rename? This guy!

[elad-custora]

We've been affected by the same issue. It looks like during the refactor process Worker has been renamed to Workers. now rake qless:work crashes. Changing Worker to Workers leads to another bug. Effectively, we cannot start new workers with the latest version (right now we're sticking to an earlier version).