consider check inputs of mb_isochrone

[andypicke]

I just spent a while debugging why my call to mb_isochrone() wasn't working, and finally realized that I was passing in profile="Driving" instead of profile="driving" to the profile input. The error message wasn't very helpful:

x <- mb_geocode("Denver,CO", output = "sf")
iso <- mb_isochrone(x,profile = "Driving", time = 5)
Error in purrr::map2():
ℹ In index: 1.
Caused by error:
! Not Found
Run rlang::last_trace() to see where the error occurred.

My suggestion would be to change

profile="driving" in the definition of mb_isochrone() to:

profile = c("driving","walking","cycling","driving-traffic"), and add the line

profile = match.arg(profile) at the top of the function.