DrupalTestCase class: Deal with this class and figure out what do we need in D8

[fran]

Smartest in D7 is ussing DrupalTestCase and seems to be a replacement for a SimpleTest class.
The questions to answer here are:

• Why is DrupalTestCase being used?
• Do we need it in SmartestD8?
• How is being done in SimpleTest 8.x?

[DavidHernandez]

This class used as replacement of the default DrupalTestCase in order to include a call to the code_coverage module. Using this class instead of the default Drupal 7 class we can add the code coverage information without hacking core.

Probably there is a better way in D8 to do this.