Update pipework regexp for sudo wrapper
Update pipework regexp for sudo wrapper

On Vagrant 1.9+ plugin gems are installed into a different folder, their path
containing the ruby version. This updates the regular expression whitelisting
the pipework script to reflect this change.

fgrehm/vagrant-lxc,fgrehm/vagrant-lxc,Val/vagrant-lxc,fgrehm/vagrant-lxc,Val/vagrant-lxc,Val/vagrant-lxc