dump function file handling

[jwaggy]

ahoy,

Long time enjoyer of this library.

Is there a reason that toml.dump doesn't open a file itself like toml.load does? If so could someone or myself add this?

[uiri]

Hello!

The intent of dump/load and dumps/loads was to mimic python's builtin json module.

I suppose there is no technical reason that dump couldn't support that usage in a backwards compatible way. If you want to open a pull request which adds that (plus tests :smile: ), I would be more than happy to take a look at it!