Enable IPv6 in Docker (#5429)

cotsog · Martin Verzilli · commit 9196a0df78d5 · 2017-12-21T14:40:38.000-03:00
diff --git a/.travis.yml b/.travis.yml
@@ -15,6 +15,8 @@ matrix:
       os: linux
 
 before_install:
+  - echo '{"ipv6":true, "fixed-cidr-v6":"2001:db8:1::/64"}' | sudo tee /etc/docker/daemon.json
+  - sudo service docker restart
   - bin/ci prepare_system
 
 install:
