Fix clippy errors.

src/parser/babel_call.rs

@@ -244,7 +244,7 @@ mod tests {
         let input = OrgSource::new("()");
         let (remaining, call) = opt(babel_call_call)(input)?;
         assert_eq!(Into::<&str>::into(remaining), "()");
-        assert!(matches!(call, None));
+        assert!(call.is_none());
         Ok(())
     }
 }

src/parser/radio_link.rs

@@ -211,7 +211,7 @@ mod tests {
                 assert_eq!(inner.children.len(), 1);
                 let child = inner
                     .children
-                    .get(0)
+                    .first()
                     .expect("Length already asserted to be 1.");
                 assert!(matches!(child, Object::PlainText(_)));
                 assert_eq!(child.get_standard_properties().get_source(), "bar");
@@ -260,7 +260,7 @@ mod tests {
                 assert_eq!(inner.children.len(), 1);
                 let child = inner
                     .children
-                    .get(0)
+                    .first()
                     .expect("Length already asserted to be 1.");
                 assert!(matches!(child, Object::Bold(_)));
                 assert_eq!(child.get_standard_properties().get_source(), "*bar* ");
@@ -270,20 +270,5 @@ mod tests {
             }
         };
         Ok(())
-
-        // assert_eq!(
-        //     first_paragraph
-        //         .children
-        //         .get(1)
-        //         .expect("Len already asserted to be 3"),
-        //     &Object::RadioLink(RadioLink {
-        //         source: "*bar* ",
-        //         children: vec![Object::Bold(Bold {
-        //             source: "*bar* ",
-        //             children: vec![Object::PlainText(PlainText { source: "bar" })]
-        //         })],
-        //         path: "*bar* "
-        //     })
-        // );
     }
 }