Just wondering, if the user wants to run DTS using the configuration yaml
file or the environment variables instead of the command line args, are
they supposed to run main.py by itself after setup? Because right now, it
won't run without the --tarball or --dpdk-tree args, even if it's specified
in the config file. It seems like it just ignores whatever was specified in
the command line if it's specified in the yaml file, but won't execute
without the command line args either.