Add "update-vendor.sh" script and vendor our current deps (minus Docker, since that'd make a circle)

Also, updated .travis.yml to use the new "vendor" directory (since this is pretty pointless without that :D)

Signed-off-by: Andrew Page <admwiggin@gmail.com>
Run update-vendor.sh to vendor our deps

Signed-off-by: Andrew Page <admwiggin@gmail.com>
Merge pull request #140 from tianon/vendor

Add "update-vendor.sh" script and vendor our current deps...
Docker 'runin' demands passing flags before 'nsenter' cli option.
Docker does not require RunIn API. Hence that API has been removed.
nsinit CLI has been modified to work around the nsenter changes.

Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)
Check for "nsenter" in args before parsing flags. Addressed comments.
Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)
Remove debug message.
Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)