added initial isPrime function
added initial function to find N number of primes and save them to an array
added initial make_table function and renamed functions to be more idiomatic
updated ReadMe.
Added comments, and a formatting function so the table looks halfway decent on std out
put functions into a Primes class, privatized certain methods, and created a new function to solely do creation of the table.
renamed main to primes.rb
added test file, and one initial test.
updated file name to be primes instead of main
return table in case you'd like to do something with it later, and for testing purposes
Added some comments and a few new tests
added some error handling for create_n_primes_table
added setup functions for each test class, and added a test for negative numbers