binary-search: Add topics
binary-search: Add topics

closes #864

mweb/python,smalley/python,pheanex/xpython,N-Parsons/exercism-python,smalley/python,jmluy/xpython,jmluy/xpython,pheanex/xpython,exercism/xpython,behrtam/xpython,mweb/python,exercism/python,behrtam/xpython,exercism/python,N-Parsons/exercism-python,exercism/xpython