vendor: Update vishvanana/netlink dependency.

This updates the netlink dependency to include recent updates, including a fix when setting prosmic mode on a bridge and additions for creating qdisc/classes/filters. This is necessary for some upcoming additions to CNI

vendor/github.com/vishvananda/netlink/.travis.yml

@@ -4,5 +4,10 @@ before_script:
   - sudo sed -i -e 's/^Defaults\tsecure_path.*$//' /etc/sudoers
   # modprobe ip_gre or else the first gre device can't be deleted
   - sudo modprobe ip_gre
+  # modprobe nf_conntrack for the conntrack testing
+  - sudo modprobe nf_conntrack
+  - sudo modprobe nf_conntrack_netlink
+  - sudo modprobe nf_conntrack_ipv4
+  - sudo modprobe nf_conntrack_ipv6
 install:
   - go get github.com/vishvananda/netns