Update board.py

assert for edge < instead of <=
Append solutions with blanks and same letters
Merge pull request #2 from flibustenet/master

Merge changes by flibustenet (show blanks in lower case; allow words to end on last column/row; add scrabble bonus).
Merge branch 'testing' into blanks_with_same_letters
update README with the possibility of blanks replacing same letters
update README with command line for unittest
Merge remote-tracking branch 'origin' into blanks_with_same_letters

Conflicts:
	board.py
Merge pull request #5 from flibustenet/blanks_with_same_letters

Blanks with same letters, exceptions with tests