test(more): add a test for more when called without arg

tests/test_more.rs

@@ -0,0 +1,8 @@
+use common::util::*;
+
+#[test]
+fn test_more_no_arg() {
+    let (_, mut ucmd) = at_and_ucmd!();
+    let result = ucmd.run();
+    assert!(!result.success);
+}

tests/tests.rs

@@ -75,6 +75,7 @@ generic! {
     "ls", test_ls;
     "mkdir", test_mkdir;
     "mktemp", test_mktemp;
+    "more", test_more;
     "mv", test_mv;
     "numfmt", test_numfmt;
     "nl", test_nl;