Add logging

[dangelic]

We need logging for development and production mode, as console.log is not sufficient. Console.log lacks granularity and features like log exports etc.. Also, console.log does not distinguish between different environments like dev or prod.

• This includes choosing a decent logger

I've chosen Winston as our logger as it is widespread, lightweight, general and serves our purpose to log different log-levels like info, warn or fatal.

• This also includes implementing the logger in the whole code to log the triggering of certain functions and possible errors or warns.

Overall, Winston should help us to enhance our code quality

[dangelic]

State: Winston is there and lies in /src/logging.ts (branch: feature/error-handling)

We have to:

a) replace all console.logs with Winston logs
b) add sufficient and appropriate logs (warns, infos, fatals, ...) throughout the code