Implemented stackwidget style for checkmark widgets

uhabits-android/src/main/res/xml/widget_checkmark_stack_info.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2016 Álinson Santos Xavier <isoron@gmail.com>
+  ~
+  ~ This file is part of Loop Habit Tracker.
+  ~
+  ~ Loop Habit Tracker is free software: you can redistribute it and/or modify
+  ~ it under the terms of the GNU General Public License as published by the
+  ~ Free Software Foundation, either version 3 of the License, or (at your
+  ~ option) any later version.
+  ~
+  ~ Loop Habit Tracker is distributed in the hope that it will be useful, but
+  ~ WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+  ~ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+  ~ more details.
+  ~
+  ~ You should have received a copy of the GNU General Public License along
+  ~ with this program. If not, see <http://www.gnu.org/licenses/>.
+  -->
+
+<!-- TODO need to change preview image here -->
+
+<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
+    android:minHeight="40dp"
+    android:minWidth="40dp"
+    android:initialLayout="@layout/widget_wrapper"
+    android:previewImage="@drawable/widget_preview_checkmark"
+    android:resizeMode="none"
+    android:updatePeriodMillis="3600000"
+    android:configure="org.isoron.uhabits.widgets.HabitPickerDialog"
+    android:widgetCategory="home_screen">
+
+</appwidget-provider>