Use OS certificate bundle

[kbrock]

Part of ManageIQ/manageiq-appliance#341

This gets database ssl keys out of /root, which is only accessible to root user, and into a standard location which is accessible to other users, namely user manageiq

1. Store the key that signed the postgres server in the standard location
2. No longer store root.crt in /root so user manageiq can use it
3. Still configure postgres for public and private key
4. No longer store postgres.key in /var/vmdb/ since postgres can not access those files.
5. No longer configure postgres with a root cert that verifies the cert of the connecting client. This is typically ssl_ca_file=root.crt. We only use server side certificates and not client side certificates.

[kbrock]

/cc @jrafanie could you take a peek to see if this works like you thought it should?

[jrafanie]

LGTM once the comments are addressed. 👍

[kbrock]

push: fixed updates

• changed unix prompt in examples
• removed comments remaining for root.crt
• fixed cert target directory to include anchors
• fixed postgres documentation link. Also changed the wording a little for that link.
• fixed markdown for postgres documentation link
• added headings for each section
• added check/command to ensure

[miq-bot]

Checked commit kbrock@e98b3f9 with ruby 2.6.3, rubocop 1.13.0, haml-lint 0.35.0, and yamllint
0 files checked, 0 offenses detected
Everything looks fine. 🍰

[miq-bot]

Checked commit kbrock@e98b3f9 with ruby 2.6.3, rubocop 1.13.0, haml-lint 0.35.0, and yamllint
0 files checked, 0 offenses detected
Everything looks fine. 👍

[Fryguy]

LGTM - @bdunne Can you take another look?