testing: Improve runtime of TNC tests by storing the SQLite DB in ramfs

This saves about 50%-70% of the time needed for scenarios that use a DB.

testing/tests/tnc/tnccs-20-pts-no-ecc/posttest.dat

@@ -5,4 +5,4 @@ moon::iptables-restore < /etc/iptables.flush
 carol::iptables-restore < /etc/iptables.flush
 dave::iptables-restore < /etc/iptables.flush
 carol::echo 1 > /proc/sys/net/ipv4/ip_forward
-moon::rm /etc/pts/config.db
+moon::umount /etc/pts