Updated gitignore to exclude the Bullet build directory.
Updated gitignore to exclude the Bullet build directory.

daviddeng/azrael,daviddeng/azrael,daviddeng/azrael,olitheolix/azrael,daviddeng/azrael,olitheolix/azrael,olitheolix/azrael,olitheolix/azrael,daviddeng/azrael,olitheolix/azrael