Wrong kwarg fitting_model value in bicubic function

[marceloandrioni]

Describe the bug

Hello, not a big problem, but I noticed that the docstring for the bicubic function shows bicubic as the default value for the fitting_model parameter (link), while in the function declaration, c_spline is the default (link).

I thought of doing a simple PR to fix this, but I am not sure which one is to be used as default.

Thank you.

[fbriol]

Thank you for your feedback. I'm willing to let you do a PR by changing the default value to 'bicubic' here.

Thank you very much for your contribution.