Enable continuous testing

Include MIT license

Add best practices for contributions

TODO (completed): Move >>> doctests from utils.py to utils_test.py

removed redundant function definition for standard dev

modified print statements in agents.py to make it work in Py3, changed utils_test.py with regard to new utils.py

Fix for #61

Update utils.py

Created grid.py from utils.py for separated 2D Grid environment.

Fixed pruning for first max node in aphabeta_search

Replaced Calls to if_ with Pythonic Syntax

Fixes Issue #29.

These functions, which I had to implement in Python 2.2, are now
available in standard Python.

modifications in README.md on format of tables

use “raise NotImplementedError” for abstract methods