scale argument does not work with values smaller than 1 (to make image smaller)

[daattali]

This is a duplicate of #10 but worded more clearly.

The scale argument seems to work with any value greater than 1, but if I want to make the resulting file smaller by using a value of 0.9 or 0.5 for example, the resulting file is a blank canvas.

[pvictor]

Currently scale parameter is expected to be an integer, I'll see if we can update the code to use a floating number.

[daattali]

It seems to work with non-integer values above 1. 1.1, 1.5 both work, but 0.9 doesn't

[pvictor]

Scale argument now accept floating numbers.

[daattali]

Verified!