pytest enhancement for soc_modules: show error details

[rleidner]

For soc modules: show detailed messages in pytest output
I am sure this will save a lot of time!

Example import problem which works in python but fails in pytest, the statement:
from aiohttp.hdrs import METH_GET, METH_POST, METH_PUT

with this enhancement it will show this new message in pytest output:
----------------------------- Captured stdout call -----------------------------
Fehler No module named 'aiohttp.hdrs'; 'aiohttp' is not a package im configuration-Modul /var/www/html/openWB/packages/modules/vehicles/vwid/soc.py

I am sure this is also applicable to other configurable modules, but I am mainly working on soc-modules...