Code review comment for lp:~david-schwarz/lava-dispatcher/ssh_qemu_clients_v3

As discussed offline, I'd like to see about merging this with what Yongqin has been working on (https://code.launchpad.net/~liuyq0307/lava-dispatcher/test-client/+merge/69757) and make the config read from a file for the boards and specific machines. One general comment here... You seem to want the job to specify the type of client to use, but I'm betting that each test machine is only going to use pretty much one type of client. Can you envision a case where you might have a conmux client that you want to suddenly use as an ssh client? I don't think it typically makes sense, but if someone has a good reason why this might happen, let me know.

I think what we really want, is a directory containing config details for specific board types:
 - bootloader commands to send for booting to the test image
 - partition offsets
 - possibly even client type specific sections

and a config file listing the boards you have in your environment, and which board_type config to use, along with any specific information, or overrides for that individual system.