Allow submitting coords/data as a tibble

[Moohan]

This change will not change or break any existing behaviour but will work if the coordinates are submitted in a tibble.

I was trying to submit coordinates in a tibble and was getting an odd error which I traced to the utils script. Since tibble inherits from data.frame it was passing the first check but was then causing an error later since x[,1] on a tibble will return a single column tibble rather than the expected vector.

All the tests pass but I didn't add any new ones as I couldn't see a way to do that without at least adding a development dependency on {tibble}

[rCarto]

Hello,
Thank you very much for raising this issue. It would be nice to accept tibbles in the pkg.
I think I'll rather go with a solution that makes data.frames defaults explicit.

[rCarto]

I think this should be enough to allow the use of tibbles. Thank you again for taking the time to prepare a PR and for pointing me in the right direction. Don't hesitate to reopen the PR if the fix does not work as intended.

[Moohan]

Great, maybe I should have just opened an issue 😆 your change works for me!