setup opennft on new stimuli computer, switch to python 3.6

The following changes were made in the SNS lab when setting up and testing the toolbox with the new Stimuli PC.

Please check the lines and add comments, in case there are specific questions.

Open Tasks for further improvements:

• Jsonlab 1.5, upgrade to latest version (fix breaking changes)
• pyqtgraph can't handle nan values and returns empty graph
• cleanup .bat script to use specific python on path XY

Sources I found, where you might get the issue:

• This shows what I am expecting in case there are NaN values in the plot data: https://stackoverflow.com/a/34919884
• https://github.com/pyqtgraph/pyqtgraph/issues/1057

Note:

• code line where the MATLAB data is used for the numpy array: https://gitlab.uzh.ch/rt_heroes/opennft/-/blob/master/opennft/opennft.py#L1850