Fix race between container create jobs during upload

During a segmented object upload, attempts are made
to create the container for the manifest and the
segment container. These jobs are currently placed
on separate threads and can occur out of order which
causes the unit test failure seen in the bug report.

The container jobs should be ordered because the
segment container job attempts to HEAD the manifest
container to determine correct storage policy.

This patch enforces ordering of the two jobs and
modifies the unit test to assert that both container
PUTs occur in the expected order.

Change-Id: If90bec126867a4be2df34067ccefee660202f59f
Closes-Bug: #1376878