Support JSON config

[lizrice]

The CIS Benchmark audit tests assume that the parameters are passed in on the command line, but in practice they could also be read from a JSON config file (/etc/docker/daemon.json by default).

[lizrice]

@robertojrojas now that we have similar support in kube-bench, is there any chance you can add the same to docker-bench for the 0.2.1 milestone?

[robertojrojas]

@lizrice sure, I'll take at what's involved.

[lizrice]

Postpone to after kube-bench / bench-common rationalisation

[monwolf]

@lizrice is there any new regarding this issue? It would be nice to be able to pass these tests against the daemon.json