the homescreen now shows the next day with a lecture

* fixed getTomorrowWeekIndex() since it would return 7 which is out of the arrays bounds
* minor clean up

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

@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:tools="http://schemas.android.com/tools"
-             xmlns:app="http://schemas.android.com/apk/res-auto"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              tools:context=".fragments.HomeFragment">