Remove all viper/cobra dependencies

[jechols]

The viper stuff for command-line args is handy, but not worth the half a billion random dependencies it pulls in. Let's figure out a cheaper way to do this. We could parse the toml manually, and probably jam together the ENV and CLI stuff in half a day.

In a very quick test, viper adds 6 megs to a stripped binary, versus about 200k for the toml parser by itself.

[jechols]

This may help: https://www.gmarik.info/blog/2019/12-factor-golang-flag-package/

Looks rudimentary and probably not quite suited to RAIS (no parsing TOML, for instance), but it could be a start