Docker example isn't working

[deinspanjer]

Found two more issues, and I'm going to give up at this point, but I wanted to offer a fix for as far as I got.

1. The docker_kwfs.sh script has two bugs:
   • The executable name should be /go/bin/keywhiz-fs as that is what is built
   • the asuser and group arguments are long options and need two hyphens rather than one.
2. The README.md instructs the user to run the container passing an argument '--debug=true'. This is an error and will cause the argument parser to mess up during parsing giving the error "keywhiz-fs: error: unexpected /secrets/kwfs, try --help"