lab1/ex5: Tests pass with incomplete solution

[dumitrache-adrian92]

An incomplete solution which only checks if the number is a palindrome in the first base of the Bases list such as this:

(define (all-palindromes? n Bases)
  (cond ((null? Bases) #t)
        ((palindrome? (num->base n (car Bases))) #t)
        (else #f)
        )
  )

will still pass the tests.

This is especially confusing for students if they end up using this function in exercise 7 as this approach will fail those tests.

At least one more test should be added to fix this.