travis: Run ubuntu14/bsd with no network

Author: scop

.travis.yml

@@ -9,7 +9,7 @@ env:
   - DIST=centos6
   - DIST=fedoradev
   - DIST=ubuntu14
-  - DIST=ubuntu14 BSD=true
+  - DIST=ubuntu14 BSD=true NETWORK=none
   - DIST=tools
 
 before_install:
@@ -18,4 +18,5 @@ before_install:
 script:
   - docker run
     -e CI=true -e DIST=$DIST -e BSD=$BSD
+    ${NETWORK:+--network $NETWORK}
     -t bash-completion:$DIST test/docker/docker-script.sh