Closes#610
Did a QA pass after reports of some issues with the vault setup.
Identified an issue where my local testing was done with 0.20.0,
resulting in some errors on 0.21.0 due to dropping --mlock.
Also did a few other general tune ups as I ran end-to-ends again using
Vault + Systemd instead of vault in dev mode.
Staging views in #minio-docs channel
@djwfyi cursory review in case I missed something.
Closes#580
I do need to do further testing beyond the patches here. But I'm going
to handle that out-of-band.
