`math:prime?` thinks all non-integers are prime

[kg583]

(import std.Math)
(math:prime? 1.5) => true

This looks to be because the check rightly finds no integer divisors of the input.

(math:divs 1.5) likewise returns [1.5] where I might've expected an error, though given that a non-integer is not valid input in this case I'm unsure if matters.

[SuperFola]

Hi there, thanks for the issue.

I've added a fix for this, checking that the number is an integer and returning false if not, instead math:prime?, and using an assert to generate an error for math:divs (I'm unsure about that one, maybe it should be [], but that feels weird having the algorithm works for invalid inputs).