Correct CA cert argument for glanceclient

Heat need to pass the CA cert to glanceclient to load image data
during stack creation when glance api is configured with SSL.
Currently the client is passing the wrong cert key to glanceclient.
The key should be 'cacert' instead of 'ca_file'.

Change-Id: Ie542dda1354776e62507240c917c1cffbc222f17
Closes-Bug: #1384626
sync oslo-incubator for request_id shim

Sync 838a2a3 oslo-incubator to get the new request_id shim, so
can introduce a deprecation warning that tells operators upgrading
from Juno that their paste.ini files need to point to oslo.middleware

This also syncs all other modules, except policy, which looks like it
needs some changes to heat thus will be handled via another patch.

Note we shouldn't remove this request_id shim until after Kilo is
branched.

Change-Id: I35125ffa263b0522ff6dd0b80b0beb3cbc79999b
Related-Bug: #1380629
Merge "sync oslo-incubator for request_id shim"
Merge "Correct CA cert argument for glanceclient"