The version file does not appear to be totally unused in all cases.  For collins_shell, and collins_notify, blake appears to have used them
https://github.com/tumblr/collins/blob/master/support/collins-shell/lib/collins_shell/cli.rb#L149
https://github.com/tumblr/collins/blob/master/support/ruby/collins-notify/lib/collins_notify/version.rb#L8
I don't know much ruby, but it seems like there are better ways to do this.  Maybe something like this.
http://stackoverflow.com/questions/3046233/get-version-of-gem-within-ruby