define a custom list of words when constructing, or use default list (via. brainstorming-a-name)
add support for passing a filename for a wordlist in the constructor
add support for passing in an array of words to the constructor
better to_s via. @meatbox on reddit
http://www.reddit.com/r/ruby/comments/1lrkin/hi_guys_i_made_my_first_ruby_game_what_do_you/cc27el8