Ignore items_after_statements Clippy pedantic lint in test suite

    error: adding items after statements is confusing, since items exist from the start of the scope
      --> tests/test_macros.rs:60:5
       |
    60 | /     fn message(cell: Cell<&str>) -> &str {
    61 | |         cell.get()
    62 | |     }
       | |_____^
       |
       = note: `-D clippy::items-after-statements` implied by `-D clippy::pedantic`
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

tests/test_macros.rs

@@ -1,4 +1,9 @@
-#![allow(clippy::eq_op, clippy::shadow_unrelated, clippy::wildcard_imports)]
+#![allow(
+    clippy::eq_op,
+    clippy::items_after_statements,
+    clippy::shadow_unrelated,
+    clippy::wildcard_imports
+)]
 
 mod common;