support for on.soundcloud links

[degendemolisher]

fixes #44
in resolve(),
get redirect link (soundcloud.com) if regex detects anything other than that (e.g. on.soundcloud.com)
regex here https://regex101.com/r/jK3gNT/1

[Aden720]

tested the sync method with these changes, and is returning the expected results. this seems like a fine solution.

[3jackdaws]

@degendemolisher can you fix the linting errors called out in the autolinter run?

You can run linting locally by doing make lint on the command line

[degendemolisher]

Should I add requests in requirements_dev.txt?

[3jackdaws]

It would be nice to avoid adding more dependencies. Can you redo the part that requires requests to use urllib?

[3jackdaws]

There's get_obj_from and get_url utility functions in util.py

[degendemolisher]

one of the testing track id is invalid iirc, I changed it to something else and the test worked

[3jackdaws]

Cool, if you push up the changed test and it passes, I'll approve