pywikibot/core test job

Craft a basic configuration file for pywikibot and invoke the test suite
via: python setup.py test

Hacks:
  - setup.py bdist the bundled httplib2, then set up PYTHONPATH to include
    externals/httplib2/python2
  - run setup.py test with http_proxy=nowhere to prevent setup.py
    from installing any dependencies from the internet

Change-Id: If1cce619137a956848f6bda27f54f2232197dad9