Release 2.0.2

Changes since v2.0.1

• Bump up MACOSX_DEPLOYMENT_TARGET to 10.7 for conda.
• Add debug.py script for debugging unit tests.
• Use automated test discovery instead of test list.
• Update to NumPy C-API 1.7.
• Move all sources to "src" sub-directory.
• Open CIF files in binary mode (required for Python 3).
• Update package to be both Python 3 and Python 2 compatible.
• Remove outdated use of diffpy.structure.

Release is also available at https://pypi.python.org/pypi.