required -m message

I enjoy using the kaggle api, I think it speeds things up for submissions, and I want to make a contribution to it.

Design wise, I think that the behavior for the -m message option should perform similarly to git. If you don't include the -m option, kaggle api should open up your default editor. By writing and saving the message in the default editor, the message will be passed along with the -m option.

However, a little more investigation leads me to see that Kaggle doesn't interpret new lines in its submission messages. There would be a weird dissonance between your 'commit' message and the actual message you see on kaggle. I think you will see \n text on kaggle instead of actual new lines.

The biggest benefit to opening up a default editor is reusing a common paradigm and having the api become a little more intuitive to use.