Bump submodules

This updates the validation support in http/srcomp and the shepherding
module to use the latest api.
Pass the directory to `find`

Running `find` without the directory specified is a GNU extension, and
does not work on BSD-like systems.
Use set -e to fail early in run-all-tests
Detect my_dir with pwd

readlink is a completely different command on BSD and, switches aside,
prints nothing if you run it on anything that isn't a symlink.