* Simplify Run(): the function that was being sent over a channel doesn't
need to close over anything except latestToken, and we don't need to
create a new one each iteration. Instead just pass the relevant items,
namely the token and sink to work on.
* Disallow the following config combinations:
1. auto_auth.method.wrap_ttl > 0 and multiple file sinks
2. auto_auth.method.wrap_ttl > 0 and single file sink with wrap_ttl > 0
3. auto_auth.method.wrap_ttl > 0 and cache.use_auto_auth_token = true
* Expose errors that occur when APIProxy is forwarding request to Vault.
* Fix merge issues.
* agent/caching: proxy redirect and non-json responses; update tests
* agent/caching: do not wrap error responses as internal errors, simply proxy them back as-is
* minor refactoring of APIProxy.Send logic
* add test case to ensure error response is not wrapped
* vault-agent-cache: squashed 250+ commits
* Add proper token revocation validations to the tests
* Add more test cases
* Avoid leaking by not closing request/response bodies; add comments
* Fix revoke orphan use case; update tests
* Add CLI test for making request over unix socket
* agent/cache: remove namespace-related tests
* Strip-off the auto-auth token from the lookup response
* Output listener details along with configuration
* Add scheme to API address output
* leasecache: use IndexNameLease for prefix lease revocations
* Make CLI accept the fully qualified unix address
* export VAULT_AGENT_ADDR=unix://path/to/socket
* unix:/ to unix://
