dir/packages for put answers and unittests.
	new file:   exercises/__init__.py
	new file:   exercises/chap2/__init__.py
	new file:   tests/__init__.py
	new file:   tests/chap2/__init__.py
added unittests and frame for q0002 of chap2
	new file:   exercises/chap2/q0002.py
	new file:   tests/chap2/q0002.py