add support for secrets

The vault password is `sekrit`, and it only has a placeholder in it.  We
will re-key to a shared password before adding real secrets.
add skelly as admin_user
fix typo
Merge djmitche/buildbot-infra:add-skelly (PR #8)
Merge pull request #9 from djmitche/add-secrets

add support for secrets
convert markdown to rst
Merge sa2ajj/buildbot-infra:rest-doc (PR #11)