Two things to note here: we unfortunately can't just exec audit, because
something needs to load the rules in beforehand.
Second, it also dies if it can't re-nice itself, so we have to give it
CAP_SYS_NICE as well as the audit caps.
I didn't add this to the default linuxkit.yml because the linuxkit/audit
repo doesn't exist yet, but we should probably (?) do that. Additionally,
we should provide the kernel parameter audit=1, otherwise according to
auditd's man pages, we can't audit some early tasks.
Closes#52
Signed-off-by: Tycho Andersen <tycho@docker.com>
