relative paths instead of absolute paths

[damianooldoni]

To improve repeatability the paths should be changed from absolute to relative.
Please, consider to use here package which is very useful as it allows finding paths from project root directory even if files are in src or if Rmd's are knitted.

Example of absolute path: https://github.com/trias-project/risk-modelling-and-mapping/blob/master/src/trias_sdm.Rmd#L47

To be rewritten as:

global <- read.csv(file = here("data", "external", "PRA", "PRA_mammals", "gbif_speciesFiles", gbif_filename))

I can assist if needed.

[amyjsdavis]

Sure! I had the paths relative to a folder in the C directory, without thinking that not everyone works from there!