morph_stats and morph_checks print their default config url

When morph_stats and morph_checks are called without specifying a config,
the default one which is hard-coded is used. This commit puts the default
config in a yaml file and the url is displayed when used.
Benefits:

1. People can see what's in the default config
2. It can serve as an example when you have no idea how morph_check/stat work.