Switch to new vendor directory layout

Fixes #113

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

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

@@ -0,0 +1,28 @@
+# NAME
+   runc exec - execute new process inside the container
+
+# SYNOPSIS
+   runc exec [command options] <container-id> <container command>
+
+Where "<container-id>" is the name for the instance of the container and
+"<container command>" is the command to be executed in the container.
+
+# EXAMPLE
+For example, if the container is configured to run the linux ps command the
+following will output a list of processes running in the container:
+
+       # runc exec <container-id> ps
+
+# OPTIONS
+   --console                                    specify the pty slave path for use with the container
+   --cwd                                        current working directory in the container
+   --env, -e [--env option --env option]        set environment variables
+   --tty, -t                                    allocate a pseudo-TTY
+   --user, -u                                   UID (format: <uid>[:<gid>])
+   --process, -p                                path to the process.json
+   --detach, -d                                 detach from the container's process
+   --pid-file                                   specify the file to write the process id to
+   --process-label                              set the asm process label for the process commonly used with selinux
+   --apparmor                                   set the apparmor profile for the process
+   --no-new-privs                               set the no new privileges value for the process
+   --cap, -c [--cap option --cap option]        add a capability to the bounding set for the process