Add 2021 test.

m-ou-se · calebcartwright · commit 4089b7da0f98 · 2021-01-01T20:31:28.000-06:00
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;
