Implement realnum::rand (#251)

Co-authored-by: Luis Moreno <morenol@users.noreply.github.com>
Co-authored-by: Lorenzo <tunedconsulting@gmail.com>

* Implement rand. Use the new derive [#default]
* Use custom range
* Use range seed
* Bump version
* Add array length checks for

Cargo.toml

@@ -2,7 +2,7 @@
 name = "smartcore"
 description = "Machine Learning in Rust."
 homepage = "https://smartcorelib.org"
-version = "0.3.0"
+version = "0.3.1"
 authors = ["smartcore Developers"]
 edition = "2021"
 license = "Apache-2.0"