Replace iso8601-duration with iso8601 crate

For one, this updates the indirect dependency `nom` from 5.x to 7.x,
which gets rid of a future incompatibility warning produced by the
compiler:

    warning: the following packages contain code that will be rejected by a future version of Rust: nom v5.1.2
    note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 67`

But to achieve that I could have updated `iso8601-duration` to 0.2.
However, the 0.2 version makes conversion into an `std::time::Duration`
weirdly hard. And I'm also confused by the fields being `f32` for no
reason I can think of. Additionally, the crate has very few users and
there is no changelog. So in general, the `iso8601` crate looks much
better. Even if it gives us date parsing, which we don't need, I think
it's still a better option.

Unfortunately, the new crate only has millisecond precision whereas the
previous one could store seconds as `f32`.

Author: LukasKalbertodt

Cargo.toml

@@ -13,7 +13,7 @@ members = ["examples/*"]
 
 [dependencies]
 async-trait = "0.1.51"
-iso8601-duration = "0.1.0"
+iso8601 = "0.6.1"
 log = "0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"

src/tasks.rs

@@ -137,8 +137,8 @@ where
     D: Deserializer<'de>,
 {
     let s = String::deserialize(deserializer)?;
-    let iso_duration = iso8601_duration::Duration::parse(&s).map_err(serde::de::Error::custom)?;
-    Ok(iso_duration.to_std())
+    let iso_duration = iso8601::duration(&s).map_err(serde::de::Error::custom)?;
+    Ok(iso_duration.into())
 }
 
 #[derive(Deserialize, Debug, Clone)]
@@ -809,7 +809,7 @@ mod test {
                     ..
                 }
             }
-            if duration == Duration::from_secs_f32(10.848957061)
+            if duration == Duration::from_millis(10_848)
         ));
     }