remove RPS from exercises
add a basic stubbing example
added code to exercises spec to test module class, ex1, ex2, and the code for those modules in exercises.rb
added ex 2 code and test conditions
added exercise 3 and spec testing conditions
added exercise 4 code and test conditions
added test code for ex6 and the code itself in exercises
added exercise 7 test code and actual code
Added completed versions of exercises.rb and it's associated spec