Refactored and added tests

* Refactored some of the methods in hangman to clean up code
* Added cucumber test to handle a game of hangman being won
Updated code in hangman.rb with a method to handle user winning
Refactored features and cucumber tests
Fixed failing cucumber test
Started implimentation of player class

* Started writing related rspec tests
* Implimented players class
Added in remaing code for handling faliure conditions