Hi Bill. Unfortunately Ubuntu pulls packages from the Debian repositories when they cut a new release, then never update them unless someone specifically requests a backport (both a hassle and takes a while to catch someone's eye). In short - not at all your fault, this is a common gotcha. ;)
We have plans afoot to add the tor-arm package to the TorProject deb repositories which will make it a little easier to upgrade... https://trac.torproject.org/projects/tor/ticket/3391
but until then I'd suggest removing the tor-arm deb, then downloading the arm tarball and simply running 'sudo ./install' from it.
Let me know if you run into any issues! -Damian