Add TextUi

src/main/java/seedu/duke/TextUi.java

@@ -0,0 +1,26 @@
+package seedu.duke;
+
+import java.io.InputStream;
+import java.io.PrintStream;
+import java.util.Scanner;
+
+public class TextUi {
+
+    private final Scanner in;
+    private final PrintStream out;
+
+    public TextUi() {
+        this(System.in, System.out);
+    }
+
+    public TextUi(InputStream in, PrintStream out) {
+        this.in = new Scanner(in);
+        this.out = out;
+    }
+
+    public String getUserCommand() {return null;}
+
+    public void showWelcomeMessage() {}
+
+    public void showGoodByeMessage() {}
+}

src/test/java/seedu/duke/TextUiTest.java

@@ -0,0 +1,4 @@
+package seedu.duke;
+
+public class TextUiTest {
+}