Added folder named biggest_difference , solution and test files.
 Added folder named calculate_coins , solution and test files.
 Added folder named contains_digit , solution and test files.
 Added folder named contains_digits , solution and test files.
 Added folder named count_consonants , solution and test files.
 Added folder named count_substrings , solution and test files.
 Added folder named count_vowels , solution and test files.
 Added folder named digit_count , solution and test files.
 Added folder named is_decreasing , solution and test files.
 Added folder named is_increasing , solution and test files.
 Added folder named is_int_palindrom , solution and test files.
 Added folder named is_number_balanced , solution and test files.
 Added folder named is_prime , solution and test files.
 Added folder named list_to_number , solution and test files.
 Added folder named main , solution and test files.
 Added folder named nth_fibonacci , solution and test files.
 Added folder named number_to_list , solution and test files.
 Added folder named prime_factorization , solution and test files.
 Added folder named prime_number_of_divisors , solution and test files.
 Added folder named sevens_in_a_row , solution and test files.