Cloudant update setup logic

[chewbranca]

We should be loading configs in setup_benchmark rather than run_benchmark so that everything necessary to run the benchmark is prepared in setup. This makes it very handy for testing out various driver functions without having to run a proper benchmark.

Having to pass the configs into run_benchmark as well is a bit awkward, but it kind of makes sense as loading the config is a different action than copying the config into the log directory for actually running the benchmark. I'm open to alternative suggestions, but I think this is fine for a first pass, especially since it allows us to develop drivers interactively.

[MatthiasLeeIBM]

How about adding something that allows us to do both the setup and start the run.

setup_run_benchmark(Opts, Configs) ->
    setup_benchmark(Opts, Configs),
    run_benchmark(Configs).

also looking for a way to exit after completion..