On October 23, 2017, mdtest was merged into IOR. Accordingly, this repo is now deprecated. If for some reason, you want the old version that was here before the merge, it is available in the ./old subdirectory.
There is however a forked version (s3_mdtest) that uses a forked modified version of vladistan/aws4c to create and configure the correct Amazon Web Services header to eventually target an S3 based platform. The forked, modified version is currently residing in the lanl branch of jti-lanl/aws4c.