I'm not happy with having two flags for each, cert and key, but I'm not sure what a prettier version could look like.

I found that when I want to communicate with strowger through my own code, in lieu of being able to do so via RPC (because the deploy process is not written in go), I need to use the command line utility - and writing the cert to a file first, then deleting it afterwards, is hacky as well, so I thought a way to specify the cert data directly would be useful.