Feature/use absolute urls for client calls

Include unit tests for RequestContext class. Revert back to using absolute instead of relative imports within SDK. Inside of client base, expand truth checking of auth_token to include more than just None.  Use absolute urls instead of relative urls when making client put, get, post, and delete calls, which means that existing section methods and tests must form an absolute url based on request context and relative paths for methods.
Correct.  The setUp and tearDown run before and after each test method. The "doCleanup" is run after the tearDown and pops and runs whatever was added to the "addCleanup" stack.  The above test just triggers the clean-up earlier than the tearDown in order to stop the mock patch from taking effect since that test runs the function that is being otherwise mocked.