Use libcontainer version tag for vendor script

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

hack/vendor.sh

@@ -61,4 +61,4 @@ mv tmp-tar src/code.google.com/p/go/src/pkg/archive/tar
 
 clone git github.com/godbus/dbus v1
 clone git github.com/coreos/go-systemd v2
-clone git github.com/docker/libcontainer bfcd86f32d22096ae69a140a1fafc1bc42391b1c
+clone git github.com/docker/libcontainer v1.0.0