The amount to pay must be sent without comma to ogone.
e.g., for 66.99 EUR, the amount sent must be 6699.
To do that, we simply applied 66.99 * 100, which
seems rather good.
However, due to the fact how floats are handled in computers,
`66.99 * 100` returns 6698.999999999999
and
`int(6698.999999999999)` returns 6698
while we expected 6699
Using `float_repr` with `0` as decimal precision
instead of using `int` solves this issue.
`float_repr(6698.999999999999, 0)` returns 6699, as expected.