This change adds the sahara key manager and converts the proxy passwords
and swift passwords to use the castellan interface.
* adding sahara key manager
* adding castellan to requirements
* removing barbicanclient from requirements
* removing sahara.utils.keymgr and related tests
* adding castellan wrapper configs to sahara list_opts
* creating a castellan validate_config to help setup
* updating documentation for castellan usage
* fixing up tests to work with castellan
* converting all proxy password usages to use castellan
* converting job binaries to use castellan when user credentials are
applied
* converting data source to use castellan when user credentials are
applied
Change-Id: I8cb08a365c6175744970b1037501792fe1ddb0c7
Partial-Implements: blueprint improved-secret-storage
Closes-Bug: #1431944
d148dd4d55