Support for python 2.6 and 2.7 CI tests

* Travis does not support old skool python
* As for Python 3, there's a lot of work that needs to be done
* See - https://travis-ci.org/wari/pyblosxom/builds/14639665 for details
* Not implemented:

  - Things like acronym file
  - Akismet tests
  - Not sure about the foo package error.