Setup logging on salt's runner `CLI` access. Fixes #5706.

Default log level is `warning`, though, since the master configuration file is shared, whatever the `log_level` defined on the master configuration file that's the value that will be used. To tweak the `salt-run` log level on the configuration file, independently from the master, you can use `cli_salt_run_log_level`(See #5609).
Merge pull request #5740 from s0undt3ch/issues/5706-runners-logging

Setup logging on salt's runner `CLI` access. Fixes #5706.