Fix count warning php 7.2

[SosthenG]

See this issue

[ddeboer]

Awesome, thanks for the fix!

Could you also add PHP 7.2 (and 7.3, if you want) to our Travis testing matrix?

[ddeboer]

Thanks! We may want to give columnHeaders an empty array as default value, but this is a good fix for now.

[ddeboer]

Tagged as 1.0.1.

[SosthenG]

Thanks! We may want to give columnHeaders an empty array as default value, but this is a good fix for now.

Yeah that's what I did first, but I thought that in case of an empty row, the condition would be true and that's probably not what's expected.