Fix Release.md - 0.5.8 Candidate
+# Release 0.5.8 (2018-11-15) (Candidate)
+
+* Add `print.rs` for print any values conveniently
+ * Implement `print` for Vector
+ * Implement `print` for Matrix
+ * Implement `print` for `f32, f64, usize, u32, u64, i32, i64`
+
# Release 0.5.7 (2018-11-13)
* Change gaussian generate method
