First integration test

This test needs neatening but it is the first example of a working
integration test

src/tests.rs

@@ -0,0 +1,28 @@
+extern crate ansi_term;
+use super::*;
+use display::format_string;
+
+// TESTS TODO:
+// handle recursive dirs
+// handle soft links
+// handle hard links
+
+#[test]
+pub fn test_main() {
+    let r = format!(
+        "{}
+{}
+{}
+{}",
+        format_string("src/test_dir", true, " 4.0K", ""),
+        format_string("src/test_dir/many", true, " 4.0K", "└─┬",),
+        format_string("src/test_dir/many/hello_file", true, " 4.0K", "  ├──",),
+        format_string("src/test_dir/many/a_file", false, "   0B", "  └──",),
+    );
+
+    assert_cli::Assert::main_binary()
+        .with_args(&["src/test_dir"])
+        .stdout()
+        .is(r)
+        .unwrap();
+}