Introduce a global settings file (ported from gitlab)

[SalomeRonja]

by @schroederb :

For the pipeline it would be useful to have a global setting File/Data base.
This would allow us to easily communicate between the different jobs, transfering intermediate results, provide paths, checking pipeline status (which job was successful) etc.
I would suggest to generate/modify this as a file automatically during the pipeline and not required as user input.
It does not need to be human readable.

[SalomeRonja]

comment by @schroederb :
For this I thought json would be nice, but type parsing is annoying there. Open for suggestions regarding the data type :)

Possible Candidates:

• Json : stupid to parse for more complex types
• pandas dataframe : ???
• Serialized Object : could have any structure, not human readable

[candidechamp]

I will start working on this global settings file after #65 is merged.