Multiple profile configuration (#45)

Adds possibility to have multiple profiles with different backup paths, retention etc.

Co-authored-by: Matt Feifarek <matt.feifarek@gmail.com>
Co-authored-by: Erik Westrup <erik.westrup@gmail.com>

etc/systemd/system/restic-check@.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Check restic backup Backblaze B2 for errors
+OnFailure=status-email-user@%n.service
+Conflicts=restic-backup.service
+Requires=nm-unmetered-connection.service
+
+[Service]
+Type=simple
+Nice=10
+# `systemd-cat` allows showing the restic output to the systemd journal
+ExecStart=bash -c 'source /etc/restic/%I.env && /usr/local/sbin/restic_check.sh | systemd-cat'