Fix Travis CI

.travis.yml

@@ -3,9 +3,11 @@ go:
 - 1.5.1
 before_install:
 - sudo mkdir --mode 0777 -p /var/ftp/incoming
+- sudo apt-get update -qq
 - sudo apt-get install -qq vsftpd
 - sudo cp $TRAVIS_BUILD_DIR/.vsftpd.conf /etc/vsftpd.conf
 - sudo service vsftpd restart
+- sudo sysctl net.ipv6.conf.lo.disable_ipv6=0
 - go get github.com/axw/gocov/gocov
 - go get github.com/mattn/goveralls
 script: