castling and can_move? methods

The castling and the can_move? methods are now working. So we will be
able to determine the most frequent ending condition.
config for deployment on heroku
Remove current user from users index
chess logic

the Board class now provides a method to check for the possibility of
making a move
Modifications for heroku
Modifications for heroku
Modifications for heroku
Modifications for heroku
Modifications for heroku
Modifications for heroku
Modifications for heroku
Modifications for heroku
Modifications for heroku
Change log level in production
Fix current_games
Merge branch 'chessboard' of https://github.com/PerezReyLorena/WE_Mini-Project into dev
Various improvements in the views
Remove sqlite gem for production
run migrations
test