Logging for bronkhorst_elflow instead of pring

[themperek]

@thirono Could you change print to logger here:
https://github.com/SiLab-Bonn/basil/blob/development/basil/HL/bronkhorst_elflow.py

Example: https://github.com/SiLab-Bonn/basil/blob/development/basil/HL/NTCRegister.py

+ format the source

[DavidLP]

Also I recommend to put a link to the protocol description and/or a few lines about the protocol. See for example how it is done in basil for other hardware here or here.

[leloup314]

@AntonioT7 you could solve this issue in your fork, would be good chance to practice ;)

[cbespin]

I am closing this as I do not see any print statements in the module anymore (whenever they got fixed).