Implement formal logging system

[BSchilperoort]

For now we return (debugging) info to the user with print statements.

Eventually we should probably change the print statements to a more formal logging system.

Originally posted by @BSchilperoort in #11 (comment)

[geek-yang]

Good point! And this logging system should output all error and warning messages in one file (e.g. like the .out file on snellius).

[BSchilperoort]

And depending on the logging level and debug level, print to terminal.