deploy: Add archipelago user and group manually

In NFS and Mount components add archipelago user manually. For NFS
permissions to work properly across all nodes, the group owner of
the exported directory must exist on all nodes and have a common
gid. Thus, prior adduser, we create archipelago group with high gid
(200) to avoid conflicts.

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>