Add test file for count command (#2358)

* Add test file for count command

* rustfmt + Clippy

crates/nu-cli/tests/commands/count.rs

@@ -0,0 +1,13 @@
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn count_columns_in_cal_table() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+        cal | count -c
+        "#
+    ));
+
+    assert_eq!(actual.out, "7");
+}

crates/nu-cli/tests/commands/mod.rs

@@ -6,6 +6,7 @@ mod autoenv_untrust;
 mod cal;
 mod cd;
 mod compact;
+mod count;
 mod cp;
 mod default;
 mod drop;