Enhances truncate() method & modifies built-in name "vars" through out the repo

Notebook with Usage Examples & Plots for rl.py

Cleans some parts of the codeBase

Added Function to Simulate Iteration in Agents

Added Details on how to view source of imported implementations

fixes probability.py, removes extra notebook, update readme.md

Added WalkSAT

Multiple updates to agents.py (WumpusEnvironment and XYEnvironment)

Fixed Outdated Idioms in Python 3 Port

IPython Notebook for logic.py

Implemented arrow shooting in Wumpus World. Wumpus Environment is now complete.

doccument -> document

In hindsight, the variable name "doc" implies we are manipulating the
document itself when, in reality, we are manipulating the index of the
document. "docid" better expresses this concept.

Added self to argument

This change is for consistency.

Cast was not needed since the return value was already being cast. Query
function changed to use heapq.nlargest() for simplicity