Add 2021 test.

m-ou-se · calebcartwright · commit f0eaaeda9eec · 2021-01-09T12:11:52.000-06:00
diff --git a/tests/target/imports_2021_edition.rs b/tests/target/imports_2021_edition.rs
@@ -0,0 +1,3 @@
+// rustfmt-edition: 2021
+
+use ::happy::new::year;
