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
Add some session/api examples

* examples/osc-lib.py - Minimal client to use ClientManager as a library
* examples/object_api.py - Example of using the Object_Store API
* examples/common.py - Basic common setup stuff that mimics OSC's
  configuration options and logging without the rest of the CLI

Change-Id: I4243a21141a821420951d4b6352d41029cdcccbc
Begin low-level API for Netowrk v2

api.network.APIv2 starts with network_list() support to flwsh out
the skeleton of the Network API.

Change-Id: I9a2b90cde84eced1f2ea6a014b769e2bae668211
Merge branch 'object-test-open' into dt-test
Merge branch 'examples' into dt-test
Merge branch 'fix-token-issue' into dt-test
Merge branch 'low-level-api-network' into dt-test