Update Rubocop

This change updates the version of Rubocop used, and makes changes to
make Rubocop happy.

It also updates to the latest version of Tomcat.
Merge branch 'update-rubocop'
Move tasks to Rakelib

After some more research, it has become apparent that the appropriate
location for custom Rake tests is actually the rakelib directory, not
the rake directory.  This change moves those files, and updates the
require statements such that none of them require require_relative any
longer.