hard-coded paths to `/net/fantasia/home/zhanxw`

I'm trying to build the tests as part of the effort to package anno for GNU Guix, but they fail because anno tries to load the priority.txt file from `/net/fantasia/home/zhanxw/anno/priority.txt` by default.

Anno should not default to loading a non-existent file.  If the file is really needed it should be part of the installation.
