fix bug in Board.get()

method would return wrong values when negative
cell coordinates would be pass that where out
of the board.
add unit tests for the Board classes
add queen bee move rule
refactor "HexBoard" API

replace method args x, y with a cell arg (x, y)
minor comment fix
Fix typo
Fix typo
find possible queen bee moves
move Piece class to its own file
fix doc string
draft for a shell client
add virtualenv folder to .gitignore
add more info to README
add stubs to the Hive class
fix Board.locate() crash

when the piece is not on the board the locate method would crash
shell client without rules
refactor board for clarity
validate_place_piece draft
map piece point of contact to board cell
use new poc2cell method in shell client