- Improved the internal behavior of some functions. The input argument of the function pdf2doi.pdf2doi_singlefile can now be either a string (with a relative o absolute path to the file to process) or a file object, open elsewhere in the code. The first input argument of all the "finder" functions now must be a file object (open elsewhere) and not a string with the file path.
- Cleaned up dependencies, removed version constraints that are not anymore necessary