Add Python language support

This commit adds a python support feature on topcoder-greed.

The class PythonLanguage implements python's language traits.
Also, a minimal python code template (Template.py) and an embeddable
test runner template (Test.py) are added. (compatible with py 2.x and 3.x)

Additional notes:
- Snapshot version was incremented to 1.5-python on the feature.
- For convenient unit testing, hamcrest-library 1.3 was added.
Merge pull request #28 from wookayin/feature/python

Add Python language support