Added end2end testcase for ResourceWarning about unclosed sockets
Added end2end testcase for ResourceWarning about unclosed sockets

Details:

* Added an end2end testcase module test_errors.py with a testcase
  that verifies that an interactive use with --warn does not issue
  a ResourceWarning (e.g. about unclosed sockets). See issue #883.

Signed-off-by: Andreas Maier <0903150dae73adcf31eccfd2633bf70bbc40bd52@gmx.de>

pywbem/pywbemtools,pywbem/pywbemtools