* Remove chat and survey plugins from the standard plugins
* Remove all related tables and settings from both plugins
using upgrade.
* Remove temporary admin notification (MDL-82297) and strings.
* PHP Unit:
- Remove chat and survey as a sample module for unit testing
replacing it with assignment module when possible (if not page).
- Remove chat and survey from bulk update test
* Behat: Remove chat and survey behat tests
All the setup/teardown/pre/post/conditions template methods
now are required to return void. This was warned with phpunit 7
and now is enforced.
At the same time, fix a few wrong function names,
provider data and param types, return statements...
It was decided to roll only configuration dates and any date related to user content
such as 'timecreated' , 'timemodified' etc should not be rolled forward.
Laurent David