* 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

1) Can't create instance of swiftclient. Since we now create
an API instance, creating a swiftclient instance won't work.
Trying to do any object related command fails.

2) Listing objects in a container fails, we depend on the
data returned in a specific way, during the API transition
this must have slipped through.

Needs regression/funcitonal tests to mame sure this doesn't
happen again.

Change-Id: I69079a0dc9f32b84e6f9307729d3dbbba549ac5e

api.object_store.APIv1 now contains the formerly top-level functions
implementing the object-store REST client. This replaces the old-style
ObjectClientv1 that is no longer necessary.

Change-Id: I7d8fea326b214481e7d6b24119bd41777c6aa968