The `pam-mount-volumes-service-type' adds additional volumes to the
pam-mount-service-type in addition to any that are already specified in
`pam-mount-rules'.
* doc/guix.texi (PAM Mount Volume Service): add documentation for
`pam-mount-service-type'.
* gnu/services/pam-mount.scm: new file.
* Makefile.am: add pam-mount tests
* tests/services/pam-mount.scm: new tests
Signed-off-by: Ludovic Courtès <ludo@gnu.org>