Values of 0 not encoded.

[rhema]

To reproduce, run the following code example from README.md

var data = [[1850, 20, 0, 1, 1017281], [1850, 20, 0, 2, 1003841]];
new CSV(data).encode();

generates the string:

"1850,20,,1,1017281
1850,20,,2,1003841"

Rather than the expected:

"1850,20,0,1,1017281
1850,20,0,2,1003841"

For my own, limited context, I added:

if (value == 0) return "0";

to the top of the stringify function. That fixed it for me. I'm not particularly familiar with this code base, so I doubt that's the right thing to do.