Travis: Network down/up for IPv6

.travis.yml

@@ -58,10 +58,13 @@ before_script:
   - lsb_release -a
   - ifconfig
   - cat /etc/network/interfaces
+  # Add an IPv6 config and restart network
+  # https://askubuntu.com/questions/103171/editing-network-interfaces-without-system-rebooting
   - if [[ "${ENABLE_IPV6}" == "YES" ]]; then 
       echo "iface lo inet6 loopback" | sudo tee -a /etc/network/interfaces;
       cat /etc/network/interfaces;
-      sudo service networking restart;
+      sudo ifdown lo;
+      sudo ifup lo;
       ifconfig;
     fi
   - pwd