Update 'run-tests.py' to invoke unittest2 correctly on Python 2.6
Merge pull request #111 from redjack/py26-tests

Update 'run-tests.py' to invoke unittest2 correctly on Python 2.6
Tests: add a script to retrieve the closest Apache mirror

See #115
Tests: use Solr 4.7.2 from nearest mirror (closes #115)
Tests: add Python 3.4 targets