relative file paths for data_input_path

[timcadman]

When I try to specify a file path relative to my working directory:

Error: './data/alspac_all.csv' does not exist in current working directory ('/Users/timcadman/OneDrive - University of Bristol/repos/lc-alspac-upload/2021-03-11_16-56-50').

• Reinstate default working directory
• Be advised: you need to cleanup the temporary directories yourself now.

Maybe I'm doing something stupid? Ah, or maybe the function changes the working directory and then it can't find the file.