+ add logout function

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

@@ -24,6 +24,7 @@
             android:id="@+id/background_module"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
+            android:gravity="center"
             android:orientation="vertical">
 
             <ImageView
@@ -41,7 +42,6 @@
                 android:layout_gravity="center_horizontal|bottom"
                 android:gravity="center_horizontal|bottom"
                 android:padding="5dp"
-                android:text="Goat"
                 android:textColor="@color/color_white"
                 android:textSize="20sp"
                 android:textStyle="bold" />