Merge branch 'SDC-436-validation' into 'master'

atdb/taskdatabase/models.py

...abase/templates/taskdatabase/failures/tasks_failures.html

...mplates/taskdatabase/failures/tasks_failures_headers.html

atdb/taskdatabase/templates/taskdatabase/index.html

...database/templates/taskdatabase/quality/quality_page.html

...e/templates/taskdatabase/validation/tasks_validation.html

...tes/taskdatabase/validation/tasks_validation_headers.html

...se/templates/taskdatabase/validation/validation_page.html

atdb/taskdatabase/urls.py

atdb/taskdatabase/views.py