Created Singleton class to clean up Environment. Then split off distance function and Singleton class into their own files, util and singleton. Removed some unnecessary output from environment unit tests and made sure that test.py initializes the environment before any tests need to use it. Started using docstrings.
test add_food that the right number of food are added
Merge branch '0.3.single' into 0.3.check

Conflicts:
	cells.py
	environment.py