02_calculator added files
Added file calculator.rb
Added Method add and subtract with two argument.
Added Method amounts to an array in the argument that inject calculate amount.
Added Method multiply but he doesn't have implementation
03_simon_says added files
03_simon_says: Added Method echo, shout, repeat (first use of cycles in Ruby) and start_of_word (with method of working with strings)
03_simon_says: Added Method first_word and titleize, but titleize have bug