Add boilerplate for root project

src/test/java/com/cleverthis/interview/SolutionTest.java

@@ -0,0 +1,30 @@
+package com.cleverthis.interview;
+
+import com.cleverthis.interview.padlock.PadlockImpl;
+import org.junit.jupiter.api.Test;
+
+import java.util.Random;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * This is a simple placeholder to show how unit test works.
+ * You can replace it with your own test.
+ */
+class SolutionTest {
+    private void solve(PadlockImpl padlock) {
+        new Solution().solve(padlock);
+    }
+
+    @Test
+    void verify(){
+        Random random = new Random();
+        PadlockImpl padlock = new PadlockImpl(random.nextInt(1, 8));
+
+        long startTime = System.currentTimeMillis();
+        solve(padlock);
+        long endTime = System.currentTimeMillis();
+        assertTrue(padlock.isPasscodeCorrect());
+        System.out.println("Time usage: " + (endTime - startTime) + "ms");
+    }
+}