Use float-ord instead of quickersort

The latter has been deprecated.

Cargo.toml

@@ -25,7 +25,7 @@ name = "kurtosis"
 [dependencies]
 num-traits = "0.2"
 num-integer = "0.1"
-quickersort = "3"
+float-ord = "0.2"
 
 [dependencies.conv]
 default-features = false

src/lib.rs

@@ -84,7 +84,7 @@
 #![no_std]
 
 extern crate conv;
-extern crate quickersort;
+extern crate float_ord;
 #[cfg(feature = "serde")]
 #[macro_use]
 extern crate serde;

src/quantile.rs

@@ -2,7 +2,7 @@ use core;
 use core::cmp::min;
 
 use conv::{ApproxFrom, ConvAsUtil, ConvUtil, ValueFrom};
-use quickersort::sort_floats;
+use float_ord::sort as sort_floats;
 
 use super::Estimate;