Add step for updating Julia packages (#2)

* Add step for updating julia packages

* Appease clippy

Authored-by: Jules Bertholet <julesbertholet@quoi.xyz>
Approved-by: Thomas Schönauer <t.schoenauer@hgs-wt.at>

src/error.rs

@@ -2,7 +2,7 @@ use std::process::ExitStatus;
 
 use thiserror::Error;
 
-#[derive(Error, Debug, PartialEq)]
+#[derive(Error, Debug, PartialEq, Eq)]
 pub enum TopgradeError {
     #[error("{0}")]
     ProcessFailed(ExitStatus),