The kolla-genpwd, kolla-mergepwd, kolla-readpwd and kolla-writepwd
commands now creates or updates passwords.yml with correct
permissions. Also they display warning message about incorrect
permissions.

Closes-Bug: #2018338
Change-Id: I4b50053ced9150499d1d09fd4a0ec2e243cf938b
Signed-off-by: Maksim Malchuk <maksim.malchuk@gmail.com>

This commit adds two new cli commands to allow an operator
to read and write passwords into a configured Hashicorp Vault
KV.

Change-Id: Icf0eaf7544fcbdf7b83f697cc711446f47118a4d