Using a different volume name for otp test, should allow tests to run

tests/otp.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 set -ex
-OVPN_DATA=basic-data
+OVPN_DATA=basic-data-otp
 CLIENT=travis-client
 IMG=kylemanna/openvpn
 OTP_USER=otp
@@ -43,8 +43,8 @@ docker run --volumes-from $OVPN_DATA --rm $IMG ovpn_getclient $CLIENT | sed 's/a
 #
 # Fire up the server
 #
-sudo iptables -N DOCKER
-sudo iptables -I FORWARD -j DOCKER
+sudo iptables -N DOCKER || echo 'Firewall already configured'
+sudo iptables -I FORWARD -j DOCKER || echo 'Forward already configured'
 # run in shell bg to get logs
 docker run --name "ovpn-test" --volumes-from $OVPN_DATA --rm -p 1194:1194/udp --privileged $IMG &