Make models and family modules to allow importing them into other python projects

[lukovdm]

I want to use Paynt as part of some other project, and thus call the Paynt library. In order for this to be possible, the models and family folders should be modules.

[randriu]

What does this achieve exactly? We often import Paynt or its modules into other projects without declaring them as packages. Is it even necessary in Python 3?

[linusheck]

This was also necessary to get PAYNT work as a library for me. For explanation see: https://docs.python.org/3/tutorial/modules.html

The init.py files are required to make Python treat directories containing the file as packages (unless using a namespace package, a relatively advanced feature). This prevents directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path. In the simplest case, init.py can just be an empty file, but it can also execute initialization code for the package or set the all variable, described later.