Not possible to get data for only one or two days

[adamhsparks]

This line checking the dates,

chirps/R/internal_functions.R

Line 303 in 7f60a8e

cond1 <- as.integer(xmax - xmin) > 1

works such that if I wanted to fetch data for 2015-01-15 - 2015-01-16 chirps will fail with the error message that the dates are out of sync with available data or that they are reversed (twisted).

[adamhsparks]

It also means you can't fetch data for just one day as the value is 0. Checking for negative values instead should work.

[adamhsparks]

@kauedesousa, I've implemented a fix. I'll write some tests to be sure that there aren't unintended side effects.

800ba70