cli.test: fail on cli tests

This cleans up the Makefile target, and drops the dependency to point to
the $root path of the repo.

Fixes https://github.com/vbatts/go-mtree/issues/98

Reported-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

test/cli.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+func main() {
+	flag.Parse()
+
+	failed := 0
+	for _, arg := range flag.Args() {
+		cmd := exec.Command("bash", arg)
+		cmd.Stderr = os.Stderr
+		cmd.Stdout = os.Stdout
+		if err := cmd.Run(); err != nil {
+			failed++
+		}
+	}
+	if failed > 0 {
+		fmt.Printf("%d FAILED tests\n", failed)
+		os.Exit(1)
+	}
+}