Tests: add HTML report generation and a workaround to bad exception handling in sikuli.

In case of exception in python code, and since a thread is running
to observe stdout, sikuli was never terminated after an exception.
Unfortunately sys.exepthook doesn't work in that version of jython/sikuli.
Test are now written inside functions witch are passed to run_test to deal
with exception.

# opcua/__init__.py

from __future__ import absolute_import

from .client import OPCUAClient

# class RootClass(object):
#     XSD = """<?xml version="1.0" encoding="ISO-8859-1" ?>
#     <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
#     </xsd:schema>
#     """
#     CTNChildrenTypes = [("OPCUAClient", OPCUAClient, "OPCUA Client")]
#