Add fragment_room_list.xml

app/src/main/res/layout/fragment_room_list.xml

+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <TextView
+        android:id="@+id/messageText"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_centerInParent="true"
+        android:visibility="gone" />
+
+    <android.support.v7.widget.RecyclerView
+        android:id="@+id/recyclerView"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:scrollbars="vertical" />
+</RelativeLayout>
\ No newline at end of file