Switch to new vendor directory layout

Fixes #113

Signed-off-by: Marcos Lilljedahl <marcosnils@gmail.com>

vendor/github.com/opencontainers/runc/man/runc-checkpoint.8.md

@@ -0,0 +1,22 @@
+# NAME
+   runc checkpoint - checkpoint a running container
+
+# USAGE
+   runc checkpoint [command options] <container-id>
+
+Where "<container-id>" is the name for the instance of the container to be
+checkpointed.
+
+# DESCRIPTION
+   The checkpoint command saves the state of the container instance.
+
+# OPTIONS
+   --image-path                 path for saving criu image files
+   --work-path                  path for saving work files and logs
+   --leave-running              leave the process running after checkpointing
+   --tcp-established            allow open tcp connections
+   --ext-unix-sk                allow external unix sockets
+   --shell-job                  allow shell jobs
+   --page-server                ADDRESS:PORT of the page server
+   --file-locks                 handle file locks, for safety
+   --manage-cgroups-mode        cgroups mode: 'soft' (default), 'full' and 'strict'.