Add AddTaskActivity, add menu + handle click AddTask button
Create Category model and add it to Task model + display it in TaskActivity
Add Category list to spinner in ActivityAddTask
Create Task database
Get Tasks from database
Fix: display task.description on TaskActivity
Add due date to Task model and database + display it in TaskActivity
Add Category model to database + use it in AddTaskActivity
[db] Add Category foreignkey to Task
Merge branch 'task-db' into add-task
Add color attribute to Category model
Can add a Task (but must restart app to see it)
Go back to MainActivity after creating a Task
Merge branch 'add-task'