Updated openstack/openstack
Project: openstack/python-openstackclient  6a4b673e8828f3fc80c86ef8bfa7f3ab5a8f720f

Update use of open() in object API

* Switch to use io.open() for py3 compatibility and simpler testing.
* Open files in 'rb' mode to avoid translation on Windows

Previously tests simply relied on files that were present in the
repository to run tests using open().  Change the filenames to ensure
that no longer happens.

requests_mock doesn't have a way to match against the request body for
PUT/POST; an attempt to add a new Matcher to do that worked but it
needs to subclass the currently private adapter._Matcher class or
duplicate most of its functionality.

Change-Id: I8c30b41db20af8ecafe67e760e872fc08adec905