Use dumux_add_test

exercises/exercise-basic/CMakeLists.txt

exercises/exercise-biomineralization/CMakeLists.txt

exercises/exercise-coupling-ff-pm/interface/CMakeLists.txt

exercises/exercise-coupling-ff-pm/models/CMakeLists.txt

exercises/exercise-coupling-ff-pm/turbulence/CMakeLists.txt

exercises/exercise-fluidsystem/CMakeLists.txt

exercises/exercise-fractures/CMakeLists.txt

exercises/exercise-grids/CMakeLists.txt

exercises/exercise-mainfile/CMakeLists.txt

exercises/exercise-properties/CMakeLists.txt

exercises/exercise-runtimeparams/CMakeLists.txt

exercises/solution/exercise-basic/CMakeLists.txt

exercises/solution/exercise-biomineralization/CMakeLists.txt

...solution/exercise-coupling-ff-pm/interface/CMakeLists.txt

...es/solution/exercise-coupling-ff-pm/models/CMakeLists.txt

...olution/exercise-coupling-ff-pm/turbulence/CMakeLists.txt

exercises/solution/exercise-fluidsystem/CMakeLists.txt

exercises/solution/exercise-fractures/CMakeLists.txt

exercises/solution/exercise-grids/CMakeLists.txt

exercises/solution/exercise-mainfile/CMakeLists.txt