Integrate the ceph s3-tests suite into automated client tests

Currently this only attempts to run the functional test suite and there are failures. Many of these failures are due to error response bodies not matching the API specs. Fixing those failures is dependent on [this](https://github.com/basho/webmachine/pull/144) webmachine pr and will be addressed in a separate set of changes.

Running the tests depends on [this](https://github.com/basho/s3-tests/pull/1) pr to the basho fork of the `s3-tests` repo that adds support for specifying a proxy host and port.