Function covid19db::dateutil::day_to_jd

pub fn day_to_jd(day: i32) -> JulianDay

Convert a day to a JulianDay

use covid19db::dateutil::*;
use julianday::JulianDay;
use chrono::NaiveDate;

assert_eq!(day_to_jd(2457096), JulianDay::from(NaiveDate::from_ymd(2015, 3, 14)));