Function wgs2bdmkt 

pub fn wgs2bdmkt(wgs: (f64, f64)) -> (f64, f64)

wgs2bdmkt 将无偏移的经纬度坐标 转换至 百度墨卡托坐标

    let (x, y) = coord_transform::wgs2bdmkt((118.0,32.0));
    assert_eq!(x, 13137176.998214714);
    assert_eq!(y, 3740943.32810748);